Ohh! There is a 96 pages (wow) book by Frederic P. Miller , Agnes F. Vandome and John McBrewster, published on february 16th 2011.
And.. its title is "Menstrual Cup".. :)!
Actually, (from the site above), "the content of this book primarily consists of articles available from Wikipedia or other free sources online." But it's fairly nice to see a book 'dedicated to'/focusing on the cups.
I first came across it on the French amazon(.fr), here is the link : http://www.amazon.fr/Menstrual-Cup-Frederic-P-Miller/dp/6134275646/ref=sr_1_2?ie=UTF8&qid=1321303974&sr=8-2
But it doesn't seem available on the US amazon, for instance (or i just couldn't find it lol), kinda too bad. :/
As a main intent, maybe this book is particularly meant for practitioners, midwives etc. ? ;-)
(My computer mouse is having problems, so i may be not able to write comments in the next hours-days - unless i buy another one just quickly ff bothers me.. ;) hm lol!)
Have fun or pleasure everyone!^