https://xgamers.gr/2012/11/%ce%b5%cf%80%ce%b9%ce%b2%ce%b5%ce%b2%ce%b1%ce%af%cf%89%cf%83%ce%b5-%cf%84%ce%b7%ce%bd-%cf%8d%cf%80%ce%b1%cf%81%ce%be%ce%b7-%cf%84%ce%b7%cf%82-source-2-%ce%b7-valve/
Επιβεβαίωσε την ύπαρξη της Source 2 η Valve