Anthony Frewin (assistant to Stanley Kubrick):
I had a friend who lived in the south of France, G. Legman. He supplied us with a lot of information about secret societies and sexual mores in Vienna at the time of Schnitzler. He also sent over a lot of illustrations of secret-society rituals and the Black Mass, mainly from the 19th century. We had a lot of illustrations, contemporary and even much older, of some ceremonies.