History of retired numbers dates back to Lou Gehrig Day
Lou Gehrig's number is retired by the Yankees on July 4th
New York Yankees Celebrate Lou Gehrig Day
New York Yankees Retired Numbers - Sports Illustrated
Lou Gehrig: Streak Consecutive Games Ends - Sports Illustrated NY
MLB's June 2 Lou Gehrig Day may revive visits to his Westchester grave
June 2 Is Now Lou Gehrig Day In Baseball - Lou Gehrig
Lou Gehrig, Biography, Statistics, Disease, & Facts
This Day In Sports: Lou Gehrig's tearful farewell
Lou Gehrig's final years
Derek Jeter will be final single-digit number retired by Yankees
Every MLB team's retired numbers