Note 10
From Reinhard Heydrich, by Joachim C. Fest— See further Notes

10 Das Schwarze Korps, memorial article in the issue of 11th June 1942. The observation that Heydrich was sometimes called 'the Blond Beast' by his followers is made by Willi Frischauer in Himmler the Evil Genius of the Third Reich(Boston and London, 1953).