1. O.S.Heavens:Optical Properties of Thin Solid Films (Dover, New York 1965) p. 51
2. O.S.Heavens: InPhysics of Thin Films, Vol. 2, ed. by G.Hass and R.E.Thun (Academic Press, New York 1964) p. 209
3. F.Abelés: IbidPhysics of Thin Films, Vol. 6 ed. by G.Hass and R.E.Thun Academic Press, New York (1971) p. 182
4. M.Born, E.Wolf:Principles of Optics (Pergamon Press, London 1975) p. 51
5. N.Barakat, F.Abu Zakhm: Solid State Science Conference, Cairo, E.A.R. (1967)