Rouens come in two distinct shapes. The Non-Industrial Rouen and the Production Rouen, which isn't considered endangered.
Murray McMurray Hatchery - Rouen Ducks
Rouen - Non-Industrial Duck - The Livestock Conservancy
Hoover's Hatchery Live Rouen Ducks, 10 ct. at Tractor Supply Co.
Khaki Campbell Duck - Breed Profile - Backyard Poultry
Blog — Heritage Poultry Conservancy
Rouen duck - Wikipedia
Rouen Duck Breed – Everything You Need to Know
Rouen Ducks For Sale
Buff or Orpington Duck - The Livestock Conservancy
Edible Traditions: Duck — Edible Boston