1. W. Wolfjochen: Tenside,12, 245–254 (1975).
2. S. Helmut: Tenside,10, 250–251 (1973).
3. F. Patat, E. Cremer, O. Bobleter: Monatsh. Chem.,83, 322 (1952).
4. N. N. Lebedev, V. F. Shvets: Kinet. Katal.,9, 418 (1968).
5. H. Zeininger, U. Onken: Chem. Eng. Techn.,42, 1220 (1970).