Killzone Shadow Fall, Other Guerrilla Games Now Stripped of Online Play

Killzone Mercenary, RIGS too - PS4 launch game Killzone Shadow Fall and its standalone co-op mode Intercept, PS Vita title

Guerrilla is shutting down multiplayer servers for three of its games

Game Informer march 2015 by josh al - Issuu

Killzone is long overdue a comeback - do it Sony, you cowards

Sony

Bristolian Gamer: January 2017

Charting the Evolution of Guerrilla Games History

Horizon Is Cool and All, but Where the Hell Is Killzone?

Horizon Forbidden West Review - An Exceedingly Clever Sequel

Official PlayStation Magazine - UK Edition September 1, 2015 (Digital)