Maybe the world's most expensive book...

To some it's just a bunch of bird drawings. To others, John James Audubon's "Birds of America" is a rare blend of art, natural history and craftsmanship, unique enough to be the world's most expensive book, expected to fetch more than $9.5 million at a London auction today.

Some of the world's wealthiest book collectors have been anticipating this auction for months: it represents a chance to own one of the best preserved editions of Aubudon's masterpiece, with its 435 revered, hand-colored illustrations. Read more in this Associated Press story about this work experts say is a vital piece of American history, at NPR online.