1. Mellor , J. W. 1932. A Comprehensive Treatise on Inorganic and Theoretical Chemistry, Vol. 12, 1London New York Toronto: Longmans, Green and Co. reprinted 1942, 1947 and 1953
2. Valentin , H. 1944. Geschichte der Pharmazie und Chemie in Form von Zeittafeln, 56Stuttgart: Wissenschaftl. Verlagsges. mbH.