The best split-screen games for PC | Digital Trends
Portal 2: Co-op Splitscreen Multiplayer Gameplay Walkthrough - GOOD GAME | Part 2 - YouTube
Uhh wtf? What's happening here? (Portal Reloaded coop in split screen, as I can't find ppl. btw it's so damn confusing, and I've played the whole singleplayer campaign...) : r/Portal
PC gamers can now play Portal 2 split-screen | PCGamesN
How To] Play Portal 2 Split Screen and With 2 PC or PS2 USB Controller Tutorial - YouTube