diff --git a/include/duckhandy/implem/scapegoat_map.inl b/include/duckhandy/implem/scapegoat_map.inl
index 971668c..945a32e 100644
--- a/include/duckhandy/implem/scapegoat_map.inl
+++ b/include/duckhandy/implem/scapegoat_map.inl
@@ -1,3 +1,20 @@
+/* Copyright 2016-2020 Michele Santullo
+ * This file is part of "duckhandy".
+ *
+ * "duckhandy" 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.
+ *
+ * "duckhandy" 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 "duckhandy".  If not, see <http://www.gnu.org/licenses/>.
+ */
+
 namespace duckmem {
 	///-------------------------------------------------------------------------
 	///-------------------------------------------------------------------------
diff --git a/include/duckhandy/implem/scapegoat_tree.inl b/include/duckhandy/implem/scapegoat_tree.inl
index 6095fc7..690f650 100644
--- a/include/duckhandy/implem/scapegoat_tree.inl
+++ b/include/duckhandy/implem/scapegoat_tree.inl
@@ -1,3 +1,20 @@
+/* Copyright 2016-2020 Michele Santullo
+ * This file is part of "duckhandy".
+ *
+ * "duckhandy" 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.
+ *
+ * "duckhandy" 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 "duckhandy".  If not, see <http://www.gnu.org/licenses/>.
+ */
+
 namespace duckmem {
 	///-------------------------------------------------------------------------
 	///-------------------------------------------------------------------------
diff --git a/include/duckhandy/implem/tree_iterator.inl b/include/duckhandy/implem/tree_iterator.inl
index f4d9507..8425641 100644
--- a/include/duckhandy/implem/tree_iterator.inl
+++ b/include/duckhandy/implem/tree_iterator.inl
@@ -1,3 +1,20 @@
+/* Copyright 2016-2020 Michele Santullo
+ * This file is part of "duckhandy".
+ *
+ * "duckhandy" 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.
+ *
+ * "duckhandy" 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 "duckhandy".  If not, see <http://www.gnu.org/licenses/>.
+ */
+
 namespace duckmem {
 	namespace Implem {
 		///---------------------------------------------------------------------
diff --git a/include/duckhandy/log2_fast.hpp b/include/duckhandy/log2_fast.hpp
index 65e5d6a..b949843 100644
--- a/include/duckhandy/log2_fast.hpp
+++ b/include/duckhandy/log2_fast.hpp
@@ -1,3 +1,20 @@
+/* Copyright 2016-2020 Michele Santullo
+ * This file is part of "duckhandy".
+ *
+ * "duckhandy" 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.
+ *
+ * "duckhandy" 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 "duckhandy".  If not, see <http://www.gnu.org/licenses/>.
+ */
+
 #ifndef id28695193476D4A9499151FC175A49196
 #define id28695193476D4A9499151FC175A49196
 
diff --git a/include/duckhandy/scapegoat_map.hpp b/include/duckhandy/scapegoat_map.hpp
index e0010fa..22c62e4 100644
--- a/include/duckhandy/scapegoat_map.hpp
+++ b/include/duckhandy/scapegoat_map.hpp
@@ -1,3 +1,20 @@
+/* Copyright 2016-2020 Michele Santullo
+ * This file is part of "duckhandy".
+ *
+ * "duckhandy" 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.
+ *
+ * "duckhandy" 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 "duckhandy".  If not, see <http://www.gnu.org/licenses/>.
+ */
+
 #ifndef idDD2D1A57ABEB4BEEA0F7E46C347D1637
 #define idDD2D1A57ABEB4BEEA0F7E46C347D1637
 
diff --git a/include/duckhandy/scapegoat_tree.hpp b/include/duckhandy/scapegoat_tree.hpp
index 362e07a..f653d18 100644
--- a/include/duckhandy/scapegoat_tree.hpp
+++ b/include/duckhandy/scapegoat_tree.hpp
@@ -1,3 +1,20 @@
+/* Copyright 2016-2020 Michele Santullo
+ * This file is part of "duckhandy".
+ *
+ * "duckhandy" 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.
+ *
+ * "duckhandy" 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 "duckhandy".  If not, see <http://www.gnu.org/licenses/>.
+ */
+
 #ifndef id79CEDB2530B54204A6BEDCBE0B767EA1
 #define id79CEDB2530B54204A6BEDCBE0B767EA1
 
diff --git a/include/duckhandy/tree_iterator.hpp b/include/duckhandy/tree_iterator.hpp
index 258d3a9..babad3f 100644
--- a/include/duckhandy/tree_iterator.hpp
+++ b/include/duckhandy/tree_iterator.hpp
@@ -1,3 +1,20 @@
+/* Copyright 2016-2020 Michele Santullo
+ * This file is part of "duckhandy".
+ *
+ * "duckhandy" 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.
+ *
+ * "duckhandy" 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 "duckhandy".  If not, see <http://www.gnu.org/licenses/>.
+ */
+
 #ifndef id6109D5EDE99D43C4909F084A231BF2C2
 #define id6109D5EDE99D43C4909F084A231BF2C2