There are two copies of The Art of Flowering Bonsai by Peter Adams currently available on Half.com (a division of ebay). One is thirty-something dollars and one is $45. Here is the link:
The Art of Flowering Bonsai
This book often sells for more. It's an excellent reference for many of the lovely flowering trees that make such beautiful bonsai. I bought a copy for $30. from this site before I posted the link here.
Joanie