John Urschel: From NFL Player to Mathematician
John Urschel, Baltimore, Offensive Line
Retiring Raven tribute: Marshal Yanda deflected praise, but few deserve it more - The Athletic
Ravens' John Urschel, lineman and PhD candidate, retires from NFL aged 26, NFL
Sara Does Science — Science Crush Friday - An NFL Player? Really?
John Urschel, Tackling Graph Theory
NFL player who retired to pursue a PhD at MIT lived on $25,000 a year
Baltimore selects Mississauga's Brent Urban, first Canadian taken in NFL draft; Ravens also pick Winnipeg's John Urschel
Ravens' John Urschel on exploring football, math, why and why not - WTOP News
Ravens OL John Urschel, 26, abruptly retires days after findings of CTE study were released – New York Daily News
John Urschel: From the NFL to MIT - WSJ