I received a real smart assed response from one of the readers to my promotion of Hoke's book (not from Steve), but the reality of the situation is the book is written with excellent instructions on how to process precious metals, what acids to use, how to test metals, and pretty much anything a layman might need to know in order to refine. The beauty of this book is that it is a "how to" book, unlike many others, and one need not have an understanding of chemistry in order to be successful. Fact is, it was written for people that are not chemically literate.
I have nothing more than a high school education, and took no chemistry classes in school. I not only learned to refine from Hoke's book, I ended up with a thriving refining business, which I sold when I retired.
I recommend the book over any other single book published. Even if you have to pay well over $100, it's a bargain. It is unlikely you'll find any more useful information, regardless of the source.
Harold