Butenandt; Schmidt-Thome Chemische Berichte, 1936 , vol. 69, p. 882,887 Full Text Show Details Ruzicka; Rosenberg Helvetica Chimica Acta, 1936 , vol. 19, p. 357,365 Full Text Show Details Butenandt; Cobler; Schmidt Chemische Berichte, 1936 , vol. 69, p. 448