1. Holden, G., Bishop, E. T., and Legge, N. R., Proc. Intern. Rubber Conf., 287 (1967).
2. Hendus, Von H., Illers, K. H., and Ropte, E., Kolloid Zeit., 216, 110 (1967).
3. Beecher, J. F., Marker, L., Bradford, R. D., and Aggarwal, S. L., J. Poly. Sci., C26, 117 (1969).
4. Kato, K., J. Poly. Sci., B4, 35 (1966).