1. Kraus, J.D.: Antennas, 2nd edn(McGraw-Hill, New York 1988)
2. Stutzman, W.L., and Thiele, G.A.: Antenna theory and design, (John Wiley & Sons, New York 1981)
3. Nakano, H.: Helical and spiral antennas—a numerical approach, (Research Studies Press, New York 1987)