Leica M 50mm Lenses Compared (x11) +Leica Lens Guide!
Leica M 50mm lens comparison: 10 fast options - Part 1. Introductions — Focus shift: a street photography blog
Leica Summicron-M 50mm f/2 M-Mount Lens in Black
Leica 50mm APO-Summicron-M ASPH f/2.0 review, sampel photos and interview with the lens designer Peter Karbe - Thorsten Overgaard's Leica Photography Pages
Leica M 50mm lens comparison: 10 fast options - Part 1. Introductions — Focus shift: a street photography blog
Leica Summicron-M 50mm f/2 Lens 11826 B&H Photo Video