Be careful what you use as a bookmark. Thousands of dollars, a Christmas card signed by Frank Baum, a Mickey Mantle rookie baseball card, a marriage certificate from 1879, a baby’s tooth, a diamond ring and a handwritten poem by Irish writer Katharine Tynan Hickson are just some of the stranger objects discovered inside books by AbeBooks.com booksellers.

I recently opened a secondhand book and an airline boarding pass from Liberia in west Africa to Fort Worth, Texas, fell to the floor. Was there a story behind this little slip of paper? Was someone fleeing from a country ravaged by two civil wars since 1989? I will never know, but used and rare booksellers discover countless objects - some mundane, some bizarre, some deeply personal - inside books as they sort and catalog books for resale