1. P. W. Knopp, L. G. Uhren, G. A. Rohlich and M. S. Nichols,J. Am. Oil Chem. Soc. 42 1965) 867.
2. I. M. Abrams, U.S. Patent 3.123.553.
3. F. Wolf and S. Wuter,Tenside 7 (1970) 140.
4. E. L. Barnhart and W. W. Eckenfelder, Industrial Waste Conf., Purdue University (1963) p. 589.
5. A. Socha and Z. Gorzka, in ?Chemistry for Protection of Environment? (edited by L. Pawlowsky, A. J. Verdier and W. J. Lacy) Elsevier, New York, (1984) p. 451.