Chris Borland Retirement: Is Football Worth It?
49ers' Chris Borland, 24, retires because of brain injury concerns - Los Angeles Times
Chris Borland stuns 49ers with retirement announcement
NFL star Chris Borland quits over head injury concerns - CBS News
Chris Borland's retirement: Is an NFL player's brain really more important than his feet?
Nonsense; Chris Borland's retirement isn't going to change the NFL
49ers ex-linebacker Chris Borland salutes Pat Tillman
Chris Borland Archives - Jeffrey Sterling, MD
San Francisco 49ers' Chris Borland retiring from NFL
Teenage Sports Blog – I say the things you won't