Hello sean r,
my top four if I was forced to choose would be...........
#1. Dr Sheltons Hygienic System Vol III.......which is an online book now.
#2. The Science and Fine Art of Fasting.......Shelton: a condensed version of the above book.
#3. Fasting Can Save Your Life .......by Shelton
#4. Fasting For Renewal of Life......by Shelton

#3 & #4 are basically updates later in his life to his main work of Vol III of seven Volumes on the Hygienic System, but Vol III (along with his voluminous work from the pioneers of Natural Hygiene, where Shelton painstakingly sifted thru all the works of the masters, and discarded the wheat from the chaff......"HUMAN LIFE: ITS PHILOSOPHY and LAWS"....these are masterpieces of healthful living: the latter of which is now a rare book to obtain..................

http://www.alibris.com/booksearch?qwork=3045299&matches=22&author=Shelton%2C+...


http://www.alibris.com/search/books/author/Shelton,%20Herbert%20M.


I have collected all of these over the years, along with all the books that I have mentioned from the links that I provided, plus many more besides.

Regards

Chrisb1.