The NFL's best players by jersey number: Nos. 50-99 - Sports Illustrated
The Best Hall of Fame Argument for Every NFL Team, News, Scores, Highlights, Stats, and Rumors
56: Gene Upshaw, The Top 100: NFL's Greatest Players (2010)
100 people who grew the NFL's business
Slippery Rock's Marcus Martin wins 2017 Gene Upshaw DII Lineman of the Year Award
56: Gene Upshaw, The Top 100: NFL's Greatest Players (2010)
The Best Player to Ever Wear Each NFL Jersey Number, News, Scores, Highlights, Stats, and Rumors
56: Gene Upshaw, The Top 100: NFL's Greatest Players (2010)
Hall of Famer, leader Upshaw dies of cancer – East Bay Times
The Top 100: NFL's Greatest Players, Packers Wiki