diff --git a/pm4py/algo/discovery/ocel/ocpn/variants/__init__.py b/pm4py/algo/discovery/ocel/ocpn/variants/__init__.py
index 4653d0ea1..a1ad8d9e4 100644
--- a/pm4py/algo/discovery/ocel/ocpn/variants/__init__.py
+++ b/pm4py/algo/discovery/ocel/ocpn/variants/__init__.py
@@ -1 +1,18 @@
+'''
+    This file is part of PM4Py (More Info: https://pm4py.fit.fraunhofer.de).
+
+    PM4Py 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.
+
+    PM4Py 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.
+
+    You should have received a copy of the GNU General Public License
+    along with PM4Py.  If not, see <https://www.gnu.org/licenses/>.
+'''
+
 from pm4py.algo.discovery.ocel.ocpn.variants import classic
diff --git a/pm4py/algo/discovery/ocel/ocpn/variants/classic.py b/pm4py/algo/discovery/ocel/ocpn/variants/classic.py
index 0d4eaacf9..cbc9163f6 100644
--- a/pm4py/algo/discovery/ocel/ocpn/variants/classic.py
+++ b/pm4py/algo/discovery/ocel/ocpn/variants/classic.py
@@ -1,3 +1,20 @@
+'''
+    This file is part of PM4Py (More Info: https://pm4py.fit.fraunhofer.de).
+
+    PM4Py 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.
+
+    PM4Py 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.
+
+    You should have received a copy of the GNU General Public License
+    along with PM4Py.  If not, see <https://www.gnu.org/licenses/>.
+'''
+
 from pm4py.objects.ocel.obj import OCEL
 from pm4py.algo.discovery.ocel.ocdfg.variants import classic as ocdfg_discovery
 from pm4py.algo.discovery.inductive import algorithm as inductive_miner
diff --git a/pm4py/algo/discovery/ocel/ocpn/variants/wo_annotation.py b/pm4py/algo/discovery/ocel/ocpn/variants/wo_annotation.py
index 0c5a8800d..911f14690 100644
--- a/pm4py/algo/discovery/ocel/ocpn/variants/wo_annotation.py
+++ b/pm4py/algo/discovery/ocel/ocpn/variants/wo_annotation.py
@@ -1,3 +1,20 @@
+'''
+    This file is part of PM4Py (More Info: https://pm4py.fit.fraunhofer.de).
+
+    PM4Py 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.
+
+    PM4Py 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.
+
+    You should have received a copy of the GNU General Public License
+    along with PM4Py.  If not, see <https://www.gnu.org/licenses/>.
+'''
+
 from pm4py.algo.discovery.ocel.ocpn.variants.classic import *
 
 # renamed
diff --git a/pm4py/meta.py b/pm4py/meta.py
index b0e6128f8..19e450f44 100644
--- a/pm4py/meta.py
+++ b/pm4py/meta.py
@@ -1,3 +1,20 @@
+'''
+    This file is part of PM4Py (More Info: https://pm4py.fit.fraunhofer.de).
+
+    PM4Py 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.
+
+    PM4Py 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.
+
+    You should have received a copy of the GNU General Public License
+    along with PM4Py.  If not, see <https://www.gnu.org/licenses/>.
+'''
+
 __name__ = 'pm4py'
 VERSION = '2.7.6'
 __version__ = VERSION
diff --git a/pm4py/visualization/dfg/variants/frequency.py b/pm4py/visualization/dfg/variants/frequency.py
index fbb2450bb..b8271b9c5 100644
--- a/pm4py/visualization/dfg/variants/frequency.py
+++ b/pm4py/visualization/dfg/variants/frequency.py
@@ -1,3 +1,20 @@
+'''
+    This file is part of PM4Py (More Info: https://pm4py.fit.fraunhofer.de).
+
+    PM4Py 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.
+
+    PM4Py 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.
+
+    You should have received a copy of the GNU General Public License
+    along with PM4Py.  If not, see <https://www.gnu.org/licenses/>.
+'''
+
 from pm4py.statistics.attributes.log import get as attr_get
 from pm4py.objects.dfg.utils import dfg_utils
 from pm4py.util import xes_constants as xes
diff --git a/pm4py/visualization/dfg/variants/performance.py b/pm4py/visualization/dfg/variants/performance.py
index 3123ebd2b..61bf0635f 100644
--- a/pm4py/visualization/dfg/variants/performance.py
+++ b/pm4py/visualization/dfg/variants/performance.py
@@ -1,3 +1,20 @@
+'''
+    This file is part of PM4Py (More Info: https://pm4py.fit.fraunhofer.de).
+
+    PM4Py 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.
+
+    PM4Py 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.
+
+    You should have received a copy of the GNU General Public License
+    along with PM4Py.  If not, see <https://www.gnu.org/licenses/>.
+'''
+
 from pm4py.statistics.attributes.log import get as attr_get
 from pm4py.objects.dfg.utils import dfg_utils
 from pm4py.util import xes_constants as xes