I bought Mrs. Chiang's Szechuan Cookbook when it first came out. It immediately became and remains my favorite Chinese cookbook. In fact, I have used it so much that I have worn it out! I take good care of my books, but years of kitchen use have put numerous stains on the pages and have broken the binding, never mind the total destruction of the dust cover! I have given this book as gifts to several friends who have enjoyed my Chinese meals (based on this book), and they are using it too.
You can also get Szechuan Home Cooking. It is just a later edition of the same book, and the only changes are in the introductory material.
Do yourself a favor and get this fabulous book before it disappears forever.
By the way, I finally replaced my worn-out copy, but have kept the old one stored sentimentally alongside--it's full of notes, like "excellent recipe", "Marc [husband] raves", "fabulous and easy."