1. The Theory of Electrons;Lorentz,1952
2. C. Kittel, Introduction to Solid State Physics, 3rd Ed., Wiley, New York, Chapter 12
3. Solid State Physics;Dekker,1962
4. Dynamic Theory of Crystal Lattices;Born,1954
5. A.R. von Hippel, Dielectric and Waves, Wiley, New York, Chapman and Hall, London, 1954, Chapter 2