Chris Borland, the 'most dangerous man in football,' traded an NFL career for an internship over CTE, Sports
Parents rethink youth football as safety fears drive NFL linebacker to retire at 24, NFL
Chris Borland stuns 49ers with retirement announcement
NFL players react to Chris Borland's surprise retirement - Sports Illustrated
Chris Borland - Wikipedia
Clarett on Chris Borland retirement: 'Lots of guys don't have a backup plan'
Health fears lead young San Francisco 49ers linebacker Chris Borland to quit NFL
49ers' Chris Borland, 24, quits NFL over concussion worries
49ers' Chris Borland Retires from NFL at Age 24
I retired from the NFL after one season - I was dubbed the most dangerous man in football after revealing my reasons why
49ers' Chris Borland retiring at 24, wary of head trauma – The Denver Post
Chris Borland retires: NFL must improve player safety - Sports Illustrated
Lowell Cohn: Chris Borland's retirement a choice to admire
Chris Borland's Early NFL Retirement Should Spark Changes at the College Level, News, Scores, Highlights, Stats, and Rumors