Links
[1] https://www.ifross.org/?q=i-free-software-open-source-software-definition
[2] https://www.ifross.org/?q=publikation/gnu-project-what-free-software
[3] http://www.gnu.org/philosophy/free-sw.html
[4] https://www.ifross.org/?q=publikation/open-source-initiative-osi-definition
[5] http://www.opensource.org/docs/definition.php
[6] https://www.ifross.org/?q=en/category/autoren/richard-stallman
[7] https://www.ifross.org/?q=publikation/why-free-software-better-open-source
[8] http://www.gnu.org/philosophy/free-software-for-freedom.html
[9] https://www.ifross.org/?q=en/category/tags/free-software