Information about the included Icon Sets is below.

Google Material Design:
License: Apache License Version 2.0
Site: https://github.com/google/material-design-icons
Direct Link: https://github.com/google/material-design-icons/archive/master.zip
Archive.org Capture of License Declaration: http://web.archive.org/web/*/https://github.com/google/material-design-icons

Templarian Material Design:
License: SIL OPEN FONT LICENSE Version 1.1
Site: https://github.com/Templarian/MaterialDesign
Direct Link: https://github.com/Templarian/MaterialDesign/archive/master.zip
Archive.org Capture of License Declaration: http://web.archive.org/web/20161227025826/https://github.com/Templarian/MaterialDesign

Android L Pack:
License: Attribution-NoDerivs 3.0 Unported (CC BY-ND 3.0)
Site: https://icons8.com/android-icons/
Direct Link: https://cdnd.icons8.com/download/android_l_icons_free.zip
Archive.org Capture of License Declaration: http://web.archive.org/web/*/https://icons8.com/license/

Nova Free Pack:
License: CC0 1.0 Universal
Site: http://www.webalys.com/nova/free-icons.html
Direct Link: http://www.webalys.com/nova/free/Nova-Free-Pack.zip
Archive.org Capture of License Declaration: http://web.archive.org/web/*/http://www.webalys.com/nova/free-icons.html