On this site everything is free of charge.
A big part of the photos we are using, are in the public domain and cannot be copyrighted.
If we  found any copyright information we tried to send a notice to the photographer, and we are giving credit to him.
If somebody finds his photo here without credit, please send me the information.
If you would like to find more information and pictures in the same theme, you may visit our study area where you will find many other photos etc. with an educational nature.