Antennas and Propagation Society Symposium 1991 Digest Antennas and Propagation Society International Symposium, 1991. AP-S. Digest. :460-463 vol.1 1991
IEEE Transactions on Microwave Theory and Techniques IEEE Trans. Microwave Theory Techn. Microwave Theory and Techniques, IEEE Transactions on. 40(6):1310-1317 Jun, 1992