I bought this book expecting something different than it actually is. It seems to be aimed at ag departments of universities, agribusiness and businesses that invest in commercial agriculture. I was hoping to find a book that would have details not only on varieties, but their care. The book has wonderful color pictures of fruit. I guess further confirmation of its commercial agricultural bias is that it doesn't have pictures of trees and foliage. Still, it's very nice to see pictures of cultivars that are less commonly sold in U.S. stores.
There are good descriptions of the fruits' characteristics. A real plus is a section in the back that shows the fruit of, and basic traits of, the most commonly used citrus rootstocks. Record frosts killed some of my citrus trees down to the graft. The rootstocks survive and it's interesting to read about them and decide whether I'd like to simply grow the rootstocks.
This book is of limited use to the citrus gardener, however. Much of the information (though not the high quality photographs) can now be found on the internet. And without details about hardiness and other individual care instructions, one gets through with it pretty early. If the book were only $20, it'd be worth having just for the picture reference. However, at $60 it's too pricey except for the deep pockets businesses it was apparently aimed at.