Just ran across this three volume set on Amazon. Does anyone own it that can give us a brief review? It is "only" around $700 US. 
[ame=http://www.amazon.com/Encyclopedia-Worlds-Zoos-3--set/dp/1579581749/ref=sr_1_10?s=books&ie=UTF8&qid=1291963685&sr=1-10]Amazon.com: Encyclopedia of the World's Zoos: 3-volume set (9781579581749): Catharine E. Bell: Books[/ame]
[ame=http://www.amazon.com/Encyclopedia-Worlds-Zoos-3--set/dp/1579581749/ref=sr_1_10?s=books&ie=UTF8&qid=1291963685&sr=1-10]Amazon.com: Encyclopedia of the World's Zoos: 3-volume set (9781579581749): Catharine E. Bell: Books[/ame]