Now that you have read the Beginner's Guide to Genetic Programming, you may (or may not!) be interested in learning more about Genetic Programming. There are several excellent books on the subject, and on subjects related to GP available from Amazon or your local bookstore. I have compiled this list from my own studies on GP and highly recommend all of the books on this page.
John R. Koza is often referred to as the father of genetic programming. His 1992 book is a landmark piece in GP theory and a must-read for anyone interested in Genetic Programming. He can, at times, be rather verbose, but the 800-page book is more of a page-turner than you would expect. He has also written three other books on Genetic Programming, all equally worthy of being read if you are interested in GP. Links to two of his four GP books are below:
Field Guide to Genetic Programming
Significantly more compact than Koza's work, the Field Guide to Genetic Programming was compiled from numerous sources to reflect the current state and practice of Genetic Programming. This book is an invaluable asset to anybody interested in Genetic Programming. I highly recommend it. It is available for free online, but it certainly doesn't hurt to have a hard copy. A link to the book on amazon is below:
Other GP Resources
There are also several other books on Genetic Programming worth reading. I've compiled a list of just a few below:
There are also several books, not specifically about GP, which you might be interested in. Work on evolution and adaptive systems is important to a study of GP. To expand your horizons beyond simply computer science, the following books might be useful: