1. Kauzmann, W., Quantum Chemistry. Academic Press, New York, 1957.
2. Ditchburn, R. S., Light. Academic Press, New York, 1976.
3. Frohlich, H., Theory of Dielectrics. Clarendon Press, Oxford, 1963, Appendix A1 (iii), p. 162.
4. Kerker, M., The Scattering of Light. Academic Press, New York, 1969.
5. Meara, M. L., Evans, G. G., Jowell, G. G. & Davies, D. P., British Food Manufacturing Industries Research Association Research Report 204 (1974).