All these monstrous crimes had a definite system of their own. There was uniformity in the murder methods: One and the same system prevailed in the construction of the gas chambers, in the mass production of the round tins containing the poisonous substances “Cyclone A” or “Cyclone B.” the ovens of the crematories are all built on the same typical lines, and one was the plan extending over all the camps of destruction. There was uniformity in the construction of the evil-smelling death machines, which the Germans referred to as “gaswagen” but which our people called the “soul destroyers;” and there was the same technical elaboration in the construction of mobile mills for grinding human bones. All this indicates one sole and evil will uniting all the individual assassins and executioners.
Source: Nuremberg Trial Proceedings Vol. 7, Fifty-Ninth Day, Thursday, 14 February 1946, Morning Session. Found at avalon.law.yale.edu/imt/02-14-46.asp