1. Yang, H.H., “Aromatic high-strength fibers”, Wiley, New York, 1989, p. 10
2. Cassidy, P.E., “Thermally stable polymers”, Marcel Dekker, New York Inc, 1980, p. 27
3. Frazer, A.H., “High temperature resistant polymers”, Wiley, New York, 1968, p. 17
4. Culbertson, B.M. and Pittman, C.U., “New Monomers and Polymers”, Plenum Press, New York, 1984, p. 22
5. Patil, P.S., Pal, R.R., Salunkhe, M.M., Maldar, N.N. and Wadgaonkar, P.P., Eur. Polym. J., 2007, 43: 5047