Both books would not be my number one and two, but are nice books to have if you want to spend your money.
The book of Mutschmann is not that spectaculair.
Die Strumpfbandnattern - Frank Mutschmann
The book of Bourguignon is a nice one with fine colourpictures and quite a lot of information.
Strumpfbandnattern - Thomas Bourguignon
My Top 2 would be: (in random order)
Strumpgbandnattern - Martin Hallmen & Jürgen Chlebowy
and
The Garter Snakes - Evolution and Ecology
I like buying books and mostly want everything there is on the subject.
From every book you learn something.
And Rick, now I know why I have that itch on my back... I'm going to shed again
