49ers ex-linebacker Chris Borland salutes Pat Tillman
49ers hit hard after unexpected offseason departures - The Boston Globe
Chris Borland talks 'early' retirement in UW-Madison guest lecture
49ers' Chris Borland Retires From NFL Over Safety Concerns
49ers ex-linebacker Chris Borland salutes Pat Tillman
Chris Borland's NFL Retirement Cost Him Millions, But Could Add 2 Decades To His Life, Statistics Show
Rookie NFL linebacker calls it quits
Why NFL star rookie Chris Borland decided to retire after one season - CBS News
NFL star Chris Borland quits over head injury concerns - CBS News