Autographs
'Wild Bill' Hickok autograph to lead sale at Heritage Auctions
'Wild Bill' Hickok and 'Buffalo Bill' Cody's autographs appear on the same book
Da Vinci, Bill Gates and Codex Leicester: why it pays to invest in genius
Sold for $5.12m in 1980, and for $30.8m in 1994, Da Vinci's Codex Leicester is a truly great investment
NBA legend Bill Russell holds rare autograph signing
He's won more championships than any other athlete in a North American sports league