Suggestions for Rocket Mass Heater Books

Hi All! I am about ready to build a rocket stove (or start building). I was wondering which book (books) the experienced might suggest as the best, most complete, most modern. I'm also not interested in a basic set of plans, rather a way discussion of principles that would allow me to scale a design effectively. Maybe a good design and a good book!

I really would like to get a book (or PDF) rather than a video series (with all due respect to Paul)

Thanks All!

Follow the link below for the book that many have used to build their own rocket mass heater:

http://www.rocketstoves.com/

The third edition was just released. It also looks like the price went up a couple US dollars too. This book will give you an understanding of principles and basic design for a rocket mass heater.

If you are looking for a book with design equations, mathematics, empirical correlations I haven't found one yet.

Thanks! Will do!