Willems; Vandenberghe Ind. chim. belge Sonderband 31. Congr. int. Chim. ind. Luettich, 1958 , p. Bd. 2, S. 476, 479 Full Text Show Details Zigeuner et al. Monatshefte fuer Chemie, 1975 , vol. 106, p. 1219,1230