MH has used this book by hays as his first school book since forever. its public domain so he can tweak it any way he wants and make it his own.
there was a fellow from england who used to post, his name was continuum force or something like that. he bought MHs expensive photocopy version and was aghast that it was basically a free book. so CF raised all kinds of hell about being ripped off and found the PDF at soilandhealth and posted it all over curezone. it was kinda funny to watch.
mike is right - get what you can out of it and dont worry about the rest. health via food is a great book.