Talisman of Zandria and Return to Zandria have gone out of print :( . Currently you can still purchase copies from some third-party sellers at Amazon, and I have some copies on hand. If you'd like to purchase a copy, please contact me. I have very few copies of Return to Zandria at this time.
Hopefully it won't be for long, and I will be able to place a reprinted and revised edition somewhere soon!