1. Mitt.:G. Heinisch, E. Luszczak undA. Mayrhofer, Mh. Chem.107, 799 (1976).
2. G. Heinisch, E. Luszczak undM. Pailer, Mh. Chem.104, 1372 (1973).
3. M. Kumagai, Nippon Kagaku Zasshi81, 489 (1960); Chem. Abstr.55, 6487.
4. K. Akagane, G. Allan undE. Passot, Pap. Puu56, 5, 11 (1974).
5. N. Clauson-Kaas undF. Limborg, Acta chem. scand.1, 619 (1947).