I'm not sure if it's been out of stock, but in their latest mailer they have copies of The Csound Book (US$37.98) and The Computer Music Tutorial ($25.00). These are publisher remainers. I bought my copies from them a year or two ago. Highly recommended if you're on a budget (the books are available from Amazon for over $50 each). Shipping is nominal. May be some other books in their catalog you might find of interest, e.g. Cope's Virtual Music and Rowe's Machine Musicianship.

http://www.labyrinthbooks.com