New Leica Lens Compendium book and a free Leica pocket guide
Erwin Puts announced on his website that there will be a new version of the Leica Lens Compendium book which should be available shortly (this explains why the old version goes for over $1000on on eBay and on Amazon).
Erwin Puts also published a 129 pages Leica Pocket Guide that can be downloaded for free here.