Although I've had some Mauser variants, I finally was able to pick up a dot and bcd Mauser. I've been concentrating my collection on US battle rifles and have some "must have" books to support that effort. I figured I should become better educated on Mausers and found these books. I'm part way through Volume IIa and absolutely must state these are the finest, most detailed and clearly "must have" books on these weapons. Thank you for your Herculean efforts. Your works will be appreciated for generations to come.