1. See, for example, BISHOP, T. G., HUGHES, C.660 (D) (1964);
2. RIDER, B. F., RUSSELL, J. L., Jr. HARRIS, D. W., et al.(1960);
3. PUGNETTI, G.(63), 22 (1963);
4. SUNDERMAN, D. N. ““, ASTM Special Tech. Publ. No. 276 (1960);
5. HART, R. G., LOUNSBURY, M., MCKAY, C. D., (1961)