Chicki Mallon's book (her daughter Patti did the updating on the edition you have) is excellent, and Chicki and Patti are subscribers to my magazine -- note they use a blurb from my mag on the back cover -- and we now share the same publisher, Avalon/Moon) but unfortunately the edition you have is now a bit dated. As I recall it was published in 1999 and researched in the year or two before that. They've done an update which should be in bookstores later this year, which should be much more on top of things.
--Lan Sluder
Belize First Magazine
http://www.belizefirst.com/