diff --git a/LBFG/types.h b/LBFG/types.h
index 3c92447f176aae463756faaf61a605105a2a6831..f95673fe6a2e33a9ea1dd25ea2b1ea859d7d0a32 100644
--- a/LBFG/types.h
+++ b/LBFG/types.h
@@ -1,3 +1,22 @@
+/* * libeisdrt - A library to calculate EIS Drts
+ * Copyright (C) 2023 Carl Klemm <carl@uvos.xyz>
+ *
+ * This file is part of libeisdrt.
+ *
+ * libeisdrt is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * libeisdrt is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with libeisdrt.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
 #pragma once
 
 #include <torch/torch.h>
diff --git a/doc/DoxygenLayout.xml b/doc/DoxygenLayout.xml
index 7a1b84f9aff45be6c691fa296d8d03558d33501a..22d753f61b642adf4f6dd09a9ca2ad56a84e7407 100644
--- a/doc/DoxygenLayout.xml
+++ b/doc/DoxygenLayout.xml
@@ -1,3 +1,22 @@
+<!--
+    libeisdrt - A library to calculate EIS Drts
+    Copyright (C) 2023 Carl Klemm <carl@uvos.xyz>
+
+    This file is part of libeisdrt.
+
+    libeisdrt is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    libeisdrt is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with libeisdrt.  If not, see <http://www.gnu.org/licenses/>.
+-->
 <doxygenlayout version="1.0">
   <!-- Generated by doxygen 1.9.3 -->
   <!-- Navigation index tabs for HTML output -->
diff --git a/drt.cpp b/drt.cpp
index 958d86ef4ab04fa0d07b6756a3ec8393c29aa3bb..a5f6e1a948a3470e42f3ff2b05fbdd4a0a232d91 100644
--- a/drt.cpp
+++ b/drt.cpp
@@ -1,3 +1,23 @@
+//
+// libeisdrt - A library to calculate EIS Drts
+// Copyright (C) 2023 Carl Klemm <carl@uvos.xyz>
+//
+// This file is part of libeisdrt.
+//
+// libeisdrt is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// libeisdrt is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with libeisdrt.  If not, see <http://www.gnu.org/licenses/>.
+//
+
 #include "eisdrt/eigendrt.h"
 
 #ifdef USE_EISGEN
diff --git a/eigentorchconversions.h b/eigentorchconversions.h
index 168fb06c9bc63fb272fb9b464b084198dd9a6a9d..58340b0c2bc5a1cc377c0fa7ccd4657e3b45514b 100644
--- a/eigentorchconversions.h
+++ b/eigentorchconversions.h
@@ -1,3 +1,22 @@
+/* * libeisdrt - A library to calculate EIS Drts
+ * Copyright (C) 2023 Carl Klemm <carl@uvos.xyz>
+ *
+ * This file is part of libeisdrt.
+ *
+ * libeisdrt is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * libeisdrt is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with libeisdrt.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
 #include <c10/core/ScalarType.h>
 #include <climits>
 #include <eisgenerator/eistype.h>
diff --git a/eisdrt/eigendrt.h b/eisdrt/eigendrt.h
index 6e467f682217ae24d848a6e226ea1cb1196d4a71..e21589f83b82c1eb623e6b470e24a2b5b51a3a20 100644
--- a/eisdrt/eigendrt.h
+++ b/eisdrt/eigendrt.h
@@ -1,3 +1,22 @@
+/* * libeisdrt - A library to calculate EIS Drts
+ * Copyright (C) 2023 Carl Klemm <carl@uvos.xyz>
+ *
+ * This file is part of libeisdrt.
+ *
+ * libeisdrt is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * libeisdrt is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with libeisdrt.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
 #pragma once
 #include <Eigen/Core>
 
diff --git a/eisdrt/eisdrt.h b/eisdrt/eisdrt.h
index 8af5df334e102b6b33e7b535addb05a184e02276..4134d25b436848f97552363ab469bd94b9299c25 100644
--- a/eisdrt/eisdrt.h
+++ b/eisdrt/eisdrt.h
@@ -1,3 +1,22 @@
+/* * libeisdrt - A library to calculate EIS Drts
+ * Copyright (C) 2023 Carl Klemm <carl@uvos.xyz>
+ *
+ * This file is part of libeisdrt.
+ *
+ * libeisdrt is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * libeisdrt is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with libeisdrt.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
 #include <eisgenerator/eistype.h>
 #include <vector>
 
diff --git a/eisdrt/eistorchdrt.h b/eisdrt/eistorchdrt.h
index 08a3bdb8396dba334463be4d67b382c0034b3c09..4f5b9f39e4850ce590bdbe4481a75afca232f7ca 100644
--- a/eisdrt/eistorchdrt.h
+++ b/eisdrt/eistorchdrt.h
@@ -1,3 +1,22 @@
+/* * libeisdrt - A library to calculate EIS Drts
+ * Copyright (C) 2023 Carl Klemm <carl@uvos.xyz>
+ *
+ * This file is part of libeisdrt.
+ *
+ * libeisdrt is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * libeisdrt is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with libeisdrt.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
 #include <eisgenerator/eistype.h>
 
 #include "torchdrt.h"
diff --git a/eisdrt/torchdrt.h b/eisdrt/torchdrt.h
index 6d26841039a429a585233f3a96ac9532ad52a8cc..6cbbd3f7456977958705e80dbdba4aee13b3339d 100644
--- a/eisdrt/torchdrt.h
+++ b/eisdrt/torchdrt.h
@@ -1,3 +1,22 @@
+/* * libeisdrt - A library to calculate EIS Drts
+ * Copyright (C) 2023 Carl Klemm <carl@uvos.xyz>
+ *
+ * This file is part of libeisdrt.
+ *
+ * libeisdrt is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * libeisdrt is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with libeisdrt.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
 #include <torch/torch.h>
 
 #include "types.h"
diff --git a/eisdrt/types.h b/eisdrt/types.h
index ead5db8cb4e4dbd09591578722558f3db466528b..1d3c0286f115958b20dcce7ced75aaf59f4d3885 100644
--- a/eisdrt/types.h
+++ b/eisdrt/types.h
@@ -1,3 +1,22 @@
+/* * libeisdrt - A library to calculate EIS Drts
+ * Copyright (C) 2023 Carl Klemm <carl@uvos.xyz>
+ *
+ * This file is part of libeisdrt.
+ *
+ * libeisdrt is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * libeisdrt is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with libeisdrt.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
 #pragma once
 
 /**
diff --git a/eistoeigen.h b/eistoeigen.h
index 89dd85760a47f0a8eae212e8b4d6194737748f97..df351474fddbbc198c0c2d1407e7efe4bb624077 100644
--- a/eistoeigen.h
+++ b/eistoeigen.h
@@ -1,3 +1,24 @@
+/* * libeisdrt - A library to calculate EIS Drts
+ * Copyright (C) 2023 Carl Klemm <carl@uvos.xyz>
+ *
+ * This file is part of libeisdrt.
+ *
+ * libeisdrt is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * libeisdrt is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with libeisdrt.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+// SPDX-License-Identifier: lgpl3
+
 #pragma once
 
 #include <Eigen/Core>
diff --git a/eistotorch.cpp b/eistotorch.cpp
index fcd12b2b6eb9996d3571c7f14330330ad99063f2..da8c885ff432478082389e09834acbdfd038f40b 100644
--- a/eistotorch.cpp
+++ b/eistotorch.cpp
@@ -1,3 +1,23 @@
+//
+// libeisdrt - A library to calculate EIS Drts
+// Copyright (C) 2023 Carl Klemm <carl@uvos.xyz>
+//
+// This file is part of libeisdrt.
+//
+// libeisdrt is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// libeisdrt is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with libeisdrt.  If not, see <http://www.gnu.org/licenses/>.
+//
+
 #include "eistotorch.h"
 #include <cassert>
 #include <cmath>
diff --git a/eistotorch.h b/eistotorch.h
index 1040f64d13cadd059e9799f30d0b6a5c2e184bef..20a724a6c3075fef6ff9dbe23a9f87624de29758 100644
--- a/eistotorch.h
+++ b/eistotorch.h
@@ -1,3 +1,22 @@
+/* * libeisdrt - A library to calculate EIS Drts
+ * Copyright (C) 2023 Carl Klemm <carl@uvos.xyz>
+ *
+ * This file is part of libeisdrt.
+ *
+ * libeisdrt is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * libeisdrt is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with libeisdrt.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
 #pragma once
 
 #include <eisgenerator/eistype.h>
diff --git a/lgpl-3.0.txt b/lgpl-3.0.txt
new file mode 100644
index 0000000000000000000000000000000000000000..0a041280bd00a9d068f503b8ee7ce35214bd24a1
--- /dev/null
+++ b/lgpl-3.0.txt
@@ -0,0 +1,165 @@
+                   GNU LESSER GENERAL PUBLIC LICENSE
+                       Version 3, 29 June 2007
+
+ Copyright (C) 2007 Free Software Foundation, Inc. <https://fsf.org/>
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+
+  This version of the GNU Lesser General Public License incorporates
+the terms and conditions of version 3 of the GNU General Public
+License, supplemented by the additional permissions listed below.
+
+  0. Additional Definitions.
+
+  As used herein, "this License" refers to version 3 of the GNU Lesser
+General Public License, and the "GNU GPL" refers to version 3 of the GNU
+General Public License.
+
+  "The Library" refers to a covered work governed by this License,
+other than an Application or a Combined Work as defined below.
+
+  An "Application" is any work that makes use of an interface provided
+by the Library, but which is not otherwise based on the Library.
+Defining a subclass of a class defined by the Library is deemed a mode
+of using an interface provided by the Library.
+
+  A "Combined Work" is a work produced by combining or linking an
+Application with the Library.  The particular version of the Library
+with which the Combined Work was made is also called the "Linked
+Version".
+
+  The "Minimal Corresponding Source" for a Combined Work means the
+Corresponding Source for the Combined Work, excluding any source code
+for portions of the Combined Work that, considered in isolation, are
+based on the Application, and not on the Linked Version.
+
+  The "Corresponding Application Code" for a Combined Work means the
+object code and/or source code for the Application, including any data
+and utility programs needed for reproducing the Combined Work from the
+Application, but excluding the System Libraries of the Combined Work.
+
+  1. Exception to Section 3 of the GNU GPL.
+
+  You may convey a covered work under sections 3 and 4 of this License
+without being bound by section 3 of the GNU GPL.
+
+  2. Conveying Modified Versions.
+
+  If you modify a copy of the Library, and, in your modifications, a
+facility refers to a function or data to be supplied by an Application
+that uses the facility (other than as an argument passed when the
+facility is invoked), then you may convey a copy of the modified
+version:
+
+   a) under this License, provided that you make a good faith effort to
+   ensure that, in the event an Application does not supply the
+   function or data, the facility still operates, and performs
+   whatever part of its purpose remains meaningful, or
+
+   b) under the GNU GPL, with none of the additional permissions of
+   this License applicable to that copy.
+
+  3. Object Code Incorporating Material from Library Header Files.
+
+  The object code form of an Application may incorporate material from
+a header file that is part of the Library.  You may convey such object
+code under terms of your choice, provided that, if the incorporated
+material is not limited to numerical parameters, data structure
+layouts and accessors, or small macros, inline functions and templates
+(ten or fewer lines in length), you do both of the following:
+
+   a) Give prominent notice with each copy of the object code that the
+   Library is used in it and that the Library and its use are
+   covered by this License.
+
+   b) Accompany the object code with a copy of the GNU GPL and this license
+   document.
+
+  4. Combined Works.
+
+  You may convey a Combined Work under terms of your choice that,
+taken together, effectively do not restrict modification of the
+portions of the Library contained in the Combined Work and reverse
+engineering for debugging such modifications, if you also do each of
+the following:
+
+   a) Give prominent notice with each copy of the Combined Work that
+   the Library is used in it and that the Library and its use are
+   covered by this License.
+
+   b) Accompany the Combined Work with a copy of the GNU GPL and this license
+   document.
+
+   c) For a Combined Work that displays copyright notices during
+   execution, include the copyright notice for the Library among
+   these notices, as well as a reference directing the user to the
+   copies of the GNU GPL and this license document.
+
+   d) Do one of the following:
+
+       0) Convey the Minimal Corresponding Source under the terms of this
+       License, and the Corresponding Application Code in a form
+       suitable for, and under terms that permit, the user to
+       recombine or relink the Application with a modified version of
+       the Linked Version to produce a modified Combined Work, in the
+       manner specified by section 6 of the GNU GPL for conveying
+       Corresponding Source.
+
+       1) Use a suitable shared library mechanism for linking with the
+       Library.  A suitable mechanism is one that (a) uses at run time
+       a copy of the Library already present on the user's computer
+       system, and (b) will operate properly with a modified version
+       of the Library that is interface-compatible with the Linked
+       Version.
+
+   e) Provide Installation Information, but only if you would otherwise
+   be required to provide such information under section 6 of the
+   GNU GPL, and only to the extent that such information is
+   necessary to install and execute a modified version of the
+   Combined Work produced by recombining or relinking the
+   Application with a modified version of the Linked Version. (If
+   you use option 4d0, the Installation Information must accompany
+   the Minimal Corresponding Source and Corresponding Application
+   Code. If you use option 4d1, you must provide the Installation
+   Information in the manner specified by section 6 of the GNU GPL
+   for conveying Corresponding Source.)
+
+  5. Combined Libraries.
+
+  You may place library facilities that are a work based on the
+Library side by side in a single library together with other library
+facilities that are not Applications and are not covered by this
+License, and convey such a combined library under terms of your
+choice, if you do both of the following:
+
+   a) Accompany the combined library with a copy of the same work based
+   on the Library, uncombined with any other library facilities,
+   conveyed under the terms of this License.
+
+   b) Give prominent notice with the combined library that part of it
+   is a work based on the Library, and explaining where to find the
+   accompanying uncombined form of the same work.
+
+  6. Revised Versions of the GNU Lesser General Public License.
+
+  The Free Software Foundation may publish revised and/or new versions
+of the GNU Lesser General Public License from time to time. Such new
+versions will be similar in spirit to the present version, but may
+differ in detail to address new problems or concerns.
+
+  Each version is given a distinguishing version number. If the
+Library as you received it specifies that a certain numbered version
+of the GNU Lesser General Public License "or any later version"
+applies to it, you have the option of following the terms and
+conditions either of that published version or of any later version
+published by the Free Software Foundation. If the Library as you
+received it does not specify a version number of the GNU Lesser
+General Public License, you may choose any version of the GNU Lesser
+General Public License ever published by the Free Software Foundation.
+
+  If the Library as you received it specifies that a proxy can decide
+whether future versions of the GNU Lesser General Public License shall
+apply, that proxy's public statement of acceptance of any version is
+permanent authorization for you to choose that version for the
+Library.
diff --git a/main.cpp b/main.cpp
index 9b1c7a065586e7514807f7d18e17e7081d476a43..00455d60ebdf09a73e8473760c15aba194609b43 100644
--- a/main.cpp
+++ b/main.cpp
@@ -1,3 +1,23 @@
+//
+// libeisdrt - A library to calculate EIS Drts
+// Copyright (C) 2023 Carl Klemm <carl@uvos.xyz>
+//
+// This file is part of libeisdrt.
+//
+// libeisdrt is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// libeisdrt is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with libeisdrt.  If not, see <http://www.gnu.org/licenses/>.
+//
+
 #include <iostream>
 #include <eisgenerator/model.h>
 #include <eisgenerator/eistype.h>
diff --git a/tensoroptions.h b/tensoroptions.h
index 858799488ed56f3052a75ff9c608f887ac468275..9b9b059674a059f65405eb50bae2b3eaf94127ca 100644
--- a/tensoroptions.h
+++ b/tensoroptions.h
@@ -1,3 +1,22 @@
+/* * libeisdrt - A library to calculate EIS Drts
+ * Copyright (C) 2023 Carl Klemm <carl@uvos.xyz>
+ *
+ * This file is part of libeisdrt.
+ *
+ * libeisdrt is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * libeisdrt is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with libeisdrt.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
 #pragma once
 #include <c10/core/ScalarType.h>
 #include <torch/torch.h>
diff --git a/testtorchdrt.cpp b/testtorchdrt.cpp
index 489fb0a8044e598910900d2ec6583ac22cd21c7c..b441b345310f53530a02b4832100cdc8e1da82b6 100644
--- a/testtorchdrt.cpp
+++ b/testtorchdrt.cpp
@@ -1,3 +1,23 @@
+//
+// libeisdrt - A library to calculate EIS Drts
+// Copyright (C) 2023 Carl Klemm <carl@uvos.xyz>
+//
+// This file is part of libeisdrt.
+//
+// libeisdrt is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// libeisdrt is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with libeisdrt.  If not, see <http://www.gnu.org/licenses/>.
+//
+
 #include <iostream>
 #include <eisgenerator/model.h>
 
diff --git a/torchdrt.cpp b/torchdrt.cpp
index 96c0f45579d42abbdf96fa63e54a65f228ac2176..d6cad8533280acf64411bf9c71153b95bb6ae9a0 100644
--- a/torchdrt.cpp
+++ b/torchdrt.cpp
@@ -1,3 +1,23 @@
+//
+// libeisdrt - A library to calculate EIS Drts
+// Copyright (C) 2023 Carl Klemm <carl@uvos.xyz>
+//
+// This file is part of libeisdrt.
+//
+// libeisdrt is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// libeisdrt is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with libeisdrt.  If not, see <http://www.gnu.org/licenses/>.
+//
+
 #include "eisdrt/torchdrt.h"
 
 #include <cassert>