1. T. MIZUTANI, Y. TAKAI and M. IEDA,Jpn J. Appl. Phys. 11 (1972) 411.
2. H. ST. ONGE and A. CROS, Conf. Elect. Insul. Dielectr. Phenom., National Academy of Science, Buck Hill Falls (1976) p. 18.
3. A. F. BURMESTER and V. J. CALDECOURT,J. Polym. Sci. Polym. Phys. 6 (1968) 1639.
4. RASHMI, PhD thesis, Indian Institute of Technology, Delhi, India (1980).
5. J. H. RANICAR, R. J. FLEMING and C. A. LEGGE,Aust. J. Phys. 24 (1971) 325.