1. D.J. Jackson: Classical Electrodynamics, 2nd edn. (Wiley, New York 1975)
2. P. Lorraine, D. Corson: Electromagnetic Fields and Waves, 2nd edn. (Freeman, New York 1970)
3. F.A. Hopf, G.I. Stegeman: Applied Classical Electrodynamics, Vol. 1: Linear Optics, Vol. 2: Non-Linear Optics (Wiley, New York 1986)
4. W. Heitler: The Quantum Theory of Radiation, 2nd edn. (Oxford Univer- sity Press, Oxford 1944)
5. R. Loudon: The Quantum Theory of Light, 2nd edn. (Oxford Science, Oxford 1983)