Circular on the Acquisition of a Doctorate Decree for Jews of German Citizenship issued by the Ministry of Science and Education [Germany]: “In agreement with the Deputy of the Fuehrer, the Reich- and Prussian Minister of the Interior and the Foreign Office, I order with immediate effect, that Jews […] who have German citizenship, are no longer admitted to the doctoral exam. Jews are also not allowed to receive a renewal of their doctoral diplomas.[…] Berlin 15 April 1937 – the Reich- and Prussian Minister of Science and Education, Signed for by Zschinzsch.”
Deutsche Wissenschaft, Erziehung und Volksbildung – 3.1937, page 224. Accessed online; Translated by Franziska Wagener 1/19/2016