node:title] San Francisco 49ers Rookie Chris Borland Retires at 24 For Concussion Concerns - Men's Journal
NFL star Chris Borland quits over head injury concerns - CBS News
Borland Effect' A Fumble For Football? Deford Says It Will Pass
San Francisco 49ers rookie LB Chris Borland retires at age 24 over head trauma concerns – New York Daily News
NFL Players Retiring Early a Trend
How many millions did 49ers' Chris Borland give up by retiring at 24?
49ers' Chris Borland Retires at 24 Due to Concerns Over Head Trauma and Safety - TV Guide
Retiring 49er Chris Borland to pay back NFL signing bonus - Sports Illustrated
What It Means to Leave Football Early - WSJ
49ers LB Chris Borland won't be last to retire early for safety reasons - Sports Illustrated
49ers Linebacker Quits After 1 Season, Citing Safety Concerns : The Two-Way : NPR
Borland: Young LB Steps Away, PFF News & Analysis
Chris Borland stuns 49ers with retirement announcement
Chris Borland - Wikipedia
49ers Chris Borland retires from football, citing concern over head injuries - Field Gulls