1. K. Chang, C. Sun IEEE Vol. MTT-31, No.2, 91 (1983)
2. Chengtian Xue Academic Conference Thesis of Electrical Industry Ministry of PRC (1986)
3. Musheng Wei Radar Measurement Technology (1981)
4. K. Bhattacharyya IEEE Vol. MTT-34, No. 11, 1223 (1986).