Patrick G. Zander, Hidden Armies of the Second World War: World War II Resistance Movements, page 119.The Czech is more dangerous and must be handled differently from Aryan peoples. Slavic man is very difficult to convince. And the consequence of this is that we must constantly keep our thumb on him so that he always remains bent, so that he will obey us and cooperate.
The same quote is cited in Robert Gerwarth's Hitler's Hangman: The Life of Heydrich, but Gerwarth doesn't include "from Aryan peoples" in the quote and also mentions, "The Nordic, Germanic man can either be convinced or broken" before "Slavic man...".
Does anyone know when Heydrich said this? Is the original German text available anywhere?
I have a feeling that Zander subsituted "Aryan peoples" for the "Nordic, Germanic man" and that's why he included it in the quote and omitted the latter.