PS4 and Xbox One vs PS3 and Xbox 360 - VGChartz Gap Charts – March 2020
What Sony's '4.2 Million PS4s Sold' Figure Actually Means - IGN
PS4 and Xbox One vs PS3 and Xbox 360 - Aligned Sales Comparison - August 2015 Update | N4G
Daniel Ahmad on Twitter: "As an aside, just because the PS4 is selling faster than the PS2 now does not mean it will outsell it in the long run. The disastrous PS3
PS4 and Xbox One vs PS3 and Xbox 360 - VGChartz Gap Charts – May 2019 Update | N4G
What Sony's '4.2 Million PS4s Sold' Figure Actually Means - IGN
First-month sales of previous consoles vs. first 24H of PS4 sales : r/PS4
PS4 sales ranked against legacy PlayStation consoles | TweakTown
PS4 vs PS3 and Xbox 360 – VGChartz Gap Charts – January 2018 Update