diff --git a/README.md b/README.md
index 4ccf9edc9e112981e3cd778330d6c938b046bc84..15fd950ec4745f6f91ac7d2c262e97c3fedf3749 100644
--- a/README.md
+++ b/README.md
@@ -10,17 +10,17 @@ The current implementation offers a set of elementary tests to check that the or
 
 # License
 
-   Copyright 2004 INAF - Osservatorio Astronomico di Cagliari
-
-   Licensed under the Apache License, Version 2.0 (the "License");
-   you may not use this file except in compliance with the License.
-   You may obtain a copy of the License at
-
-       http://www.apache.org/licenses/LICENSE-2.0
-
-   Unless required by applicable law or agreed to in writing, software
-   distributed under the License is distributed on an "AS IS" BASIS,
-   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-   See the License for the specific language governing permissions and
-   limitations under the License.
-   
\ No newline at end of file
+   Copyright (C) 2024   INAF - Osservatorio Astronomico di Cagliari
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+   
+   This program 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 General Public License for more details.
+   
+   A copy of the GNU General Public License is distributed along with
+   this program in the COPYING file. If not, see: <https://www.gnu.org/licenses/>.
diff --git a/build/README.md b/build/README.md
index 554c0d68035e9e089330df47a8493d58edb53a2f..c4b1aacde14cc277c81c2b5ce9396484f469d3ec 100644
--- a/build/README.md
+++ b/build/README.md
@@ -98,16 +98,19 @@ where the arguments must be valid paths to binary transition matrix files saved
 
 # License
 
-   Copyright 2004 INAF - Osservatorio Astronomico di Cagliari
-
-   Licensed under the Apache License, Version 2.0 (the "License");
-   you may not use this file except in compliance with the License.
-   You may obtain a copy of the License at
+# License
 
-       http://www.apache.org/licenses/LICENSE-2.0
+   Copyright (C) 2024   INAF - Osservatorio Astronomico di Cagliari
 
-   Unless required by applicable law or agreed to in writing, software
-   distributed under the License is distributed on an "AS IS" BASIS,
-   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-   See the License for the specific language governing permissions and
-   limitations under the License.
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+   
+   This program 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 General Public License for more details.
+   
+   A copy of the GNU General Public License is distributed along with
+   this program in the COPYING file. If not, see: <https://www.gnu.org/licenses/>.
diff --git a/containers/docker/README.md b/containers/docker/README.md
index d7f8e8f9b6f0681ab3513db167b6b26f136333c1..271a4a58f4ebcd60b89bfcb75ebf6155bee256f8 100644
--- a/containers/docker/README.md
+++ b/containers/docker/README.md
@@ -13,16 +13,19 @@ where `<image name>` is either `np-tmcode` or `np-tmcode-run`. One may also add
 
 # License
 
-   Copyright 2004 INAF - Osservatorio Astronomico di Cagliari
-
-   Licensed under the Apache License, Version 2.0 (the "License");
-   you may not use this file except in compliance with the License.
-   You may obtain a copy of the License at
-
-       http://www.apache.org/licenses/LICENSE-2.0
+# License
 
-   Unless required by applicable law or agreed to in writing, software
-   distributed under the License is distributed on an "AS IS" BASIS,
-   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-   See the License for the specific language governing permissions and
-   limitations under the License.
+   Copyright (C) 2024   INAF - Osservatorio Astronomico di Cagliari
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+   
+   This program 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 General Public License for more details.
+   
+   A copy of the GNU General Public License is distributed along with
+   this program in the COPYING file. If not, see: <https://www.gnu.org/licenses/>.
diff --git a/containers/singularity/README.md b/containers/singularity/README.md
index fad127007ba4d2b5d6dbfcb2f093ecab6f8b176c..12ab899c951971b9527388bfd18066841f167d75 100644
--- a/containers/singularity/README.md
+++ b/containers/singularity/README.md
@@ -20,16 +20,19 @@ where `<full path to image name>` is the name of the sif image, including full o
 
 # License
 
-   Copyright 2004 INAF - Osservatorio Astronomico di Cagliari
-
-   Licensed under the Apache License, Version 2.0 (the "License");
-   you may not use this file except in compliance with the License.
-   You may obtain a copy of the License at
-
-       http://www.apache.org/licenses/LICENSE-2.0
+# License
 
-   Unless required by applicable law or agreed to in writing, software
-   distributed under the License is distributed on an "AS IS" BASIS,
-   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-   See the License for the specific language governing permissions and
-   limitations under the License.
+   Copyright (C) 2024   INAF - Osservatorio Astronomico di Cagliari
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+   
+   This program 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 General Public License for more details.
+   
+   A copy of the GNU General Public License is distributed along with
+   this program in the COPYING file. If not, see: <https://www.gnu.org/licenses/>.
diff --git a/doc/src/README.md b/doc/src/README.md
index 28f258ffdaae2cafb173ebc798fe974d1618c1bc..ebcd796d9c5bd3bd089027e86ea374cf3920c870 100644
--- a/doc/src/README.md
+++ b/doc/src/README.md
@@ -16,16 +16,19 @@ Alternatively, you can use `make` from the project `src` folder (named `np_tmcod
 
 # License
 
-   Copyright 2004 INAF - Osservatorio Astronomico di Cagliari
-
-   Licensed under the Apache License, Version 2.0 (the "License");
-   you may not use this file except in compliance with the License.
-   You may obtain a copy of the License at
-
-       http://www.apache.org/licenses/LICENSE-2.0
+# License
 
-   Unless required by applicable law or agreed to in writing, software
-   distributed under the License is distributed on an "AS IS" BASIS,
-   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-   See the License for the specific language governing permissions and
-   limitations under the License.
+   Copyright (C) 2024   INAF - Osservatorio Astronomico di Cagliari
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+   
+   This program 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 General Public License for more details.
+   
+   A copy of the GNU General Public License is distributed along with
+   this program in the COPYING file. If not, see: <https://www.gnu.org/licenses/>.
diff --git a/src/README.md b/src/README.md
index fe3cbeef3f96417a1a708c6006a7923c7b2eb58e..5f501604424a585815bb9defe14f6f551b336266 100644
--- a/src/README.md
+++ b/src/README.md
@@ -38,16 +38,19 @@ In all cases, build commands executed through `make` will output the object file
 
 # License
 
-   Copyright 2004 INAF - Osservatorio Astronomico di Cagliari
-
-   Licensed under the Apache License, Version 2.0 (the "License");
-   you may not use this file except in compliance with the License.
-   You may obtain a copy of the License at
-
-       http://www.apache.org/licenses/LICENSE-2.0
+# License
 
-   Unless required by applicable law or agreed to in writing, software
-   distributed under the License is distributed on an "AS IS" BASIS,
-   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-   See the License for the specific language governing permissions and
-   limitations under the License.
+   Copyright (C) 2024   INAF - Osservatorio Astronomico di Cagliari
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+   
+   This program 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 General Public License for more details.
+   
+   A copy of the GNU General Public License is distributed along with
+   this program in the COPYING file. If not, see: <https://www.gnu.org/licenses/>.
diff --git a/src/scripts/README.md b/src/scripts/README.md
index de3fead8ccbe0ec983758d66a2742f14cc3625a3..e8d2b1d19679a9e0f59c51b9262809c4a76f02d1 100644
--- a/src/scripts/README.md
+++ b/src/scripts/README.md
@@ -37,16 +37,19 @@ where `LOG_FILE` must be the name of a file containing the output that would nor
 
 # License
 
-   Copyright 2004 INAF - Osservatorio Astronomico di Cagliari
-
-   Licensed under the Apache License, Version 2.0 (the "License");
-   you may not use this file except in compliance with the License.
-   You may obtain a copy of the License at
-
-       http://www.apache.org/licenses/LICENSE-2.0
+# License
 
-   Unless required by applicable law or agreed to in writing, software
-   distributed under the License is distributed on an "AS IS" BASIS,
-   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-   See the License for the specific language governing permissions and
-   limitations under the License.
+   Copyright (C) 2024   INAF - Osservatorio Astronomico di Cagliari
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+   
+   This program 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 General Public License for more details.
+   
+   A copy of the GNU General Public License is distributed along with
+   this program in the COPYING file. If not, see: <https://www.gnu.org/licenses/>.
diff --git a/test_data/README.md b/test_data/README.md
index 5926500edd6b7edbbbc4c666a4ad6abb769cddb8..0a6fe1530fafe69dc511927836551fb4e21953ff 100644
--- a/test_data/README.md
+++ b/test_data/README.md
@@ -62,16 +62,19 @@ were the different lines have the following roles:
 
 # License
 
-   Copyright 2004 INAF - Osservatorio Astronomico di Cagliari
-
-   Licensed under the Apache License, Version 2.0 (the "License");
-   you may not use this file except in compliance with the License.
-   You may obtain a copy of the License at
+# License
 
-       http://www.apache.org/licenses/LICENSE-2.0
+   Copyright (C) 2024   INAF - Osservatorio Astronomico di Cagliari
 
-   Unless required by applicable law or agreed to in writing, software
-   distributed under the License is distributed on an "AS IS" BASIS,
-   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-   See the License for the specific language governing permissions and
-   limitations under the License.
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+   
+   This program 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 General Public License for more details.
+   
+   A copy of the GNU General Public License is distributed along with
+   this program in the COPYING file. If not, see: <https://www.gnu.org/licenses/>.