[5] Chielmetti F.:  Phys. Letters, 12, 1964, 210-2.
[7] Peřina J.:  J. Czech. Phys., B17, 1967, 1086-97.
[8] Mandel L.: Pгogress in Optics. Vol. II (Amsterdam:  North - Holland),  1963, p. 183.
[14] Morse P. M., and Feshbach H.: Methods of Theoretical Physics. (New Yoгk: McGгaw-Hill), 1953.