diff --git a/gprMax/subgrids/base.py b/gprMax/subgrids/base.py
index 1923e69f..9ba9ee82 100644
--- a/gprMax/subgrids/base.py
+++ b/gprMax/subgrids/base.py
@@ -1,3 +1,20 @@
+# Copyright (C) 2015-2019: The University of Edinburgh
+#                 Authors: Craig Warren and Antonis Giannopoulos
+#
+# This file is part of gprMax.
+#
+# gprMax 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.
+#
+# gprMax 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 gprMax.  If not, see <http://www.gnu.org/licenses/>.
 from ..grid import FDTDGrid
 
 from ..materials import Material
diff --git a/gprMax/subgrids/multi.py b/gprMax/subgrids/multi.py
index 60151d0f..39b72822 100644
--- a/gprMax/subgrids/multi.py
+++ b/gprMax/subgrids/multi.py
@@ -1,3 +1,20 @@
+# Copyright (C) 2015-2019: The University of Edinburgh
+#                 Authors: Craig Warren and Antonis Giannopoulos
+#
+# This file is part of gprMax.
+#
+# gprMax 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.
+#
+# gprMax 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 gprMax.  If not, see <http://www.gnu.org/licenses/>.
 from ..receivers import Rx
 
 
diff --git a/gprMax/subgrids/precursor_nodes.py b/gprMax/subgrids/precursor_nodes.py
index 6e8a3890..3b96b07f 100644
--- a/gprMax/subgrids/precursor_nodes.py
+++ b/gprMax/subgrids/precursor_nodes.py
@@ -1,3 +1,20 @@
+# Copyright (C) 2015-2019: The University of Edinburgh
+#                 Authors: Craig Warren and Antonis Giannopoulos
+#
+# This file is part of gprMax.
+#
+# gprMax 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.
+#
+# gprMax 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 gprMax.  If not, see <http://www.gnu.org/licenses/>.
 import numpy as np
 from scipy import interpolate
 import sys
diff --git a/gprMax/subgrids/precursor_nodes_filtered.py b/gprMax/subgrids/precursor_nodes_filtered.py
index 145330cd..c8a0d41d 100644
--- a/gprMax/subgrids/precursor_nodes_filtered.py
+++ b/gprMax/subgrids/precursor_nodes_filtered.py
@@ -1,3 +1,20 @@
+# Copyright (C) 2015-2019: The University of Edinburgh
+#                 Authors: Craig Warren and Antonis Giannopoulos
+#
+# This file is part of gprMax.
+#
+# gprMax 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.
+#
+# gprMax 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 gprMax.  If not, see <http://www.gnu.org/licenses/>.
 import numpy as np
 from scipy import interpolate
 import sys
diff --git a/gprMax/subgrids/subgrid_hsg.py b/gprMax/subgrids/subgrid_hsg.py
index 29be160d..47003c96 100644
--- a/gprMax/subgrids/subgrid_hsg.py
+++ b/gprMax/subgrids/subgrid_hsg.py
@@ -1,3 +1,20 @@
+# Copyright (C) 2015-2019: The University of Edinburgh
+#                 Authors: Craig Warren and Antonis Giannopoulos
+#
+# This file is part of gprMax.
+#
+# gprMax 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.
+#
+# gprMax 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 gprMax.  If not, see <http://www.gnu.org/licenses/>.
 from .base import SubGridBase
 from ..cython.fields_updates_hsg import cython_update_is
 from ..cython.fields_updates_hsg import cython_update_magnetic_os
diff --git a/gprMax/subgrids/user_objects.py b/gprMax/subgrids/user_objects.py
index ec3c2d90..d481a5d5 100644
--- a/gprMax/subgrids/user_objects.py
+++ b/gprMax/subgrids/user_objects.py
@@ -1,3 +1,20 @@
+# Copyright (C) 2015-2019: The University of Edinburgh
+#                 Authors: Craig Warren and Antonis Giannopoulos
+#
+# This file is part of gprMax.
+#
+# gprMax 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.
+#
+# gprMax 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 gprMax.  If not, see <http://www.gnu.org/licenses/>.
 from .subgrid_hsg import SubGridHSG as SubGridHSGUser
 from .multi import ReferenceRx as ReferenceRxUser
 from ..exceptions import CmdInputError