1. J.W. Mink IEEE Vol. MTT-34, No.2, 273, (1986).
2. L. Wandinger, V. Nalbandian IEEE Vol. MTT-31, No.2, 189, (1983)
3. P.F. Goldsmith report at Chong-shan University (1985)
4. Jun-lin Qiu Laser Resonator
5. Wei-ming Yu, Hong-liang Zhao Graduate thesis, Nankai University (1986)