How the Madden NFL videogame was developed – GranneBlog
OTL: The Franchise - ESPN
Madden NFL Covers Through the Years, Gallery, History, Buying
Madden NFL 99 - Wikipedia
A Comprehensive Guide to Pro Football Video Game Covers : r/nfl
John Madden Football (1990 video game) - Wikipedia
John Madden: The Best 'Madden NFL' Games of All Time, According to Critics
John Madden Football gameplay (PC Game, 1988)