1. V. A. Fok,Studies in Propagation of Radio Waves, Second Collection [in Russian], Izd. Akad. Nauk SSSR, Moscow-Leningrad (1948), p. 40.
2. O. Tukizi,IRE Trans. Ant. Propag., AP-7, No. 3, 261 (1959).
3. M. B. Kanevskii,Izv. Vyssh. Uchebn. Zaved., Radiofiz.,9, No. 5, 867 (1966).
4. S. Rotheram,Marconi Rev. 37, No. 192, 18 (1974).
5. V. E. Grikulov,Izv. Vyssh. Uchebn. Zaved., Radiofiz.,23, No. 9, 1038 (1980).