De Diesbach et al. Helvetica Chimica Acta, 1951 , vol. 34, p. 1050,1059 Full Text Show Details de Diesbach et al. Helvetica Chimica Acta, 1934 , vol. 17, p. 113,122 Helvetica Chimica Acta, 1940 , vol. 23, p. 469,481