Sony: PS3 and PS4 cross-play is 'technically possible' (update) - Polygon
How to Play PS3 Games on the PS4 (with Pictures) - wikiHow
Sony PS4 vs PS3 | Trusted Reviews
Amazon.com: Premium Video Game Box Protector Case compatible for PS4 games, XBOX1 games, PS3 games - God of War, The Witcher, Marvels Spider Man, the last part of us, Red dead redemption,