Tobler et al. Helvetica Chimica Acta, Engi-Festband <1941> 100 Full Text Show Details v. Braun; Manz Justus Liebigs Annalen der Chemie, 1931 , vol. 488, p. 111,115, 116 Justus Liebigs Annalen der Chemie, 1932 , vol. 496, p. 170,191 Full Text Show Details Tobler et al. Helvetica Chimica Acta, Engi-Festband <1941> 100, 104