1. Hoffmann, E., and Bursztyn, B., J. Oil Col. Chem. Assoc., 47, 871 (1964).
2. Whiteley, P., J. Oil Col. Chem. Assoc., 43, 842 (1960).
3. Whiteley, P., J. Oil Col. Chem. Assoc., 45, 803 (1962).
4. Whiteley, P., J. Oil Col. Chem. Assoc., 48, 172 (1965).