1. D. Liu, “A dual-band antenna for cellular applications, ”in Proc. IEEE Antennas Propagat. Soc. Int. Symp., vol. 2, June 21–26, 1998, pp. 786–789.
2. R. Schlub, D. V. Thiel, J. W. Lu, and S. G. O‟Keefe, “Dual -band six-element switched parasitic array for smart antenna cellular communications systems”, Electron. Lett., vol. 36, pp. 1342–1343, 2000.
3. Dual-frequency strip-sleeve monopole for laptop computers;Ali;IEEE Trans. Antennas Propagat.,1999
4. D. Liu, “A multi-branch monopole antenna for dual-band cellular applications”, in Proc. IEEE Antennas Propagation Soc. Int. Symp., vol. 3, July 11–16, 1999, pp. 1578–1581.
5. Multi-circular loop monopole antenna;Song;Electron. Lett.,2000