DE 1165021, Bork, Karl-Heinz; Brückner, Klaus & Irmscher, Klaus, "Verfahren zur Herstellung von 16α-Methyl-16β-halogenmethyl-17-ketosteroiden [Process for the preparation of 16α-methyl-16β-halomethyl-17-ketosteroids]", published 1964-03-12, assigned to Merck AG