Helpful Score: 1
This book is the latest in my quest to know EVERYTHING about natural fertility awareness. It is by far the best resource I have on my bookshelf right now. It is harder reading than the rest, but is thoroughly documented and easily applicable. It goes through practically everything one might encounter in tracking a woman's cycle and backs up each application point with research and statistics. I highly recommend reading this book if you want to know lots of details about Natural Family Planning, but it isn't necessary just for learning the method.