A mule goes to a Kiwanis luncheon; vintage photos show what happened next
Charlie-O — Baseball's Favorite Mule, by Michael Murphy, SMC Sports Journalism
SABR Digital Library: Mustaches and Mayhem: 1972-74 Oakland A's – Society for American Baseball Research
A's celebrate 50 historic years in Oakland
When Oakland A's owner Charlie Finley pulled out all the stops for Opening Day
Charlie O. The Mule Photobomb - 1974 World Series Interview with Steve Garvey and Sal Bando.
Charlie O - Oakland - LocalWiki
83 Charlie O The Mule Stock Photos, High-Res Pictures, and Images - Getty Images
FINLEY YEARS – Oakland Athletics History
83 Charlie O The Mule Stock Photos, High-Res Pictures, and Images - Getty Images