Andrew Brestansky Photography - Leica Summicron-M 50mm f/2
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 50mm f/2 SUMMICRON-M (1979-today)
Leica Summicron DR Review (Summicron 50mm f2 DR - Dual Range)