1. Lepin, P. andA. Bromberg, J. Phys. Chem., U.S.S.R.15, 673 (1941).
2. Yadava, B. P., J. Ind. Chem. Soc.20, 110, 223 (1943).
3. Bhattacharya, A. K., J. Ind. Chem. Soc.28, 179 (1951).
4. Tuorilla, P., Kolloid-Beih.27, 44 (1928).
5. Bhattacharya, A. K., J. Ind. Chem. Soc.29, 687 (1952).