by Sievenpiper, D. F., Dawson, D. C., Jacob, M. M., Kanar, T., Sanghoon Kim, Jiang Long, Quarfoth, R. G.
Published in IEEE transactions on antennas and propagation (01.01.2012)

by Slaby, R G, Quarfoth, G R, McConnachie, G A
Published in Journal of communication (01.01.1976)