THE RELEVANT QUEER: David Kopay, One of America's First Openly Gay Professional Athletes
Homosexuality in American football - Wikipedia
Carl Nassib coming out doesn't just make history; he could save lives
Missouri defensive end, NFL prospect Michael Sam announces he is gay
Missouri DL and NFL hopeful: 'I am an openly, proud gay man'
Football star says he's gay - POLITICO
Dave Kopay knows what questions should be asked by NFL - The Washington Post
Kopay: Apologizes to Aikman
10 NFL Stars Who've Come Out as Gay or Bisexual
NFL's First Gay Star on Michael Sam and His Own Shocking Decision to Come Out in 1975: 'I Was Desperate' – The Hollywood Reporter
Former NFL player turned gay rights activist Wade Davis worked on Sam announcement – The Denver Post
Sunday Q&A: David Kopay sees the payoff in Michael Sam's NFL future – Daily News
N.F.L. Prospect Michael Sam Proudly Says What Teammates Knew: He's Gay - The New York Times
Cheers for Carl Nassib show a football culture that's changing