Please see the introduction to this and other articles by Prof. Dr. Walter Groß which can be viewed here. That page gives a more detailed reference …
HEILIG IST DAS BLUT (BLOOD IS HOLY) BY DR. WALTER GROSS, AUGUST 7TH 1935
HEILIG IST DAS BLUT (BLOOD IS HOLY) BY DR. WALTER GROSS, AUGUST 7TH 1935