From Charlie O. to O.co Coliseum, the A's Have History - The New York Times

Step Inside: Oakland Coliseum - Home of the Oakland Athletics - Ticketmaster Blog

Oakland's baseball legacy is bigger than the A's

Oakland Athletics: First Mascot - Charlie O the Mule

Excerpt: Dynastic, Bombastic, Fantastic: Reggie, Rollie, Catfish & Charlie Finley's Swingin' A's - Baseball ProspectusBaseball Prospectus

Switching Sox: When the A's almost moved in - South Side Sox

Charlie-O — Baseball's Favorite Mule, by Michael Murphy, SMC Sports Journalism

Scenes from an afternoon at Oakland Coliseum — now a sore sight for few eyes

The O.co Coliseum: A Blast From The Past - Bleed Cubbie Blue

Can This Man Keep the A's in Oakland? - The New York Times