Good book on tunnels and tunnel rats in Viet Nam.

Like the person who asked the question about tunnel rats, I am also curious to learn more. All I have been able to find so far is one book. It is called _The tunnels of Cu Chi_, and was published in the late 1980's. Sorry I don't have the full citation; I read a library copy and returned it already. It was an excellent overall book, I thought. Pretty well balanced in presenting info from the viewpoint of both sides, in a more or less neutral way. The book goes a little off the topic of tunnels and tunnel rats in describing various above ground battles, but the best parts of the book are when the authors are writing about events directly connected to the tunnels. The logistics and the endurance on the part of the Viet Cong to be able to build and live in the tunnels for weeks at a time, and the incredible bravery of the US soldiers who went into them are both just astounding. I higly recommend this book. I think I heard of one titled _Tunnel Rats_, but haven't been able to find it yet. _The tunnels of Cu Chi_ is about 350 pages long, and was hard to put down. I hope that there are more books and other info on the topic, and/or that people interview more of the soldiers and write about it.