San Francisco 49ers - Wikipedia
Sourdough Sam (San Francisco 49ers), SportsMascots Wikia
San Francisco 49ers - Wikipedia
Choosing Sides: How To Pick Between The Ravens And The 49ers : NPR
How every NFL team got its name
Sourdough Sam, American Football Wiki
Sourdough Sam, American Football Wiki
San Francisco 49ers - Wikipedia
Sourdough Sam (San Francisco 49ers), SportsMascots Wikia