Retired Uniform Numbers in the American League
Every MLB team's retired numbers – NBC Sports Chicago
Mets to retire numbers for Doc Gooden and Darryl Strawberry – NBC
What the Yankees' uniform number crunch could cost MLB's managers
Blue Jays' All-Time Retired Numbers
Retired Numbers, History
Blue Jays un-retire #12 for new reliever Jordan Hicks - Bluebird Banter
Chicago Cubs - Wikipedia
The 9 greatest players in Toronto Blue Jays history
Mets Retire Willie Mays's Number at Old-Timers Day - The New York