I've read with a lot of interest this book written by Michaela Merk.
She brings a very pragmatic and scientific approach on sales forces motivation. Many of the strategies presented here could be cascaded to other field than luxury. Even if I'm not a sales person, some of them remind me my own management experience with my hierarchy.
Diverse & rich testimonials are very relevants, and perfectly illustrate theories developed.
More over, this book is really accessible for non English Native like I’m am and it's a real pleasure to go through it!
I strongly recommend to buy this book, and keep it always near by for quick memo!