Crystal_Clear_Icons_-_LGPL_2.1.txt

The Crystal Clear icon set was created by 
Everaldo Coelho, https://www.everaldo.com/

All Icons are free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. This library 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. 

License details:
Visit https://www.everaldo.com/crystal/?action=license for details.