1. Nye, J.F.: 1957, ‘Physical Properties of Crystals’ Clarendon Press, Oxford.
2. Ward, I.M.: 1971, ‘Mechanical Properties of Solid Polymers’ Wiley, London.
3. Hadley, D.W., and Ward, I.M.: 1973, Rep. Prog. Physics 38, 1143.
4. Ward, I.M.: ‘Structure and Properties of Oriented Polymers’ 1975, Applied Science Publishers, London.
5. Darlington, M.W., and Saunders, D.W.: 1975, ‘Structure and Properties of Oriented Polymers’ Chapter 10 Ed. I.M. Ward, Applied Science Publishers, London.