1. Elliot, A. & Ambrose, E.J., Discuss. Faraday Soc., 1950, 9, 246.
2. Dobb, M.G. & McIntyre, J.E., Adv. Polymer Sci., 1984, 60/61, 61.
3. Kwolek, S.L., Morgan, P.W. & Schaefgen, J.R., in Encyclopedia of Polymer Science and Engineering, 2nd edn., Wiley-Interscience, New York, 1988, vol. 9, p. 1.
4. Percec, V., Mol. Cryst. Liq. Cryst.,1988, 155(B), 1.
5. Wegner, G., J. Physique, 1988, 49, 6815.