1. G. A. Lenkova, Avtometriya, No. 5, 16 (1995) [Optoelectr., Instrum. and Data Process. No. 5, 15 (1995)].
2. Y. Li and E. Wolf, Opt. Commum. 39(4), 211 (1981).
3. Y. Li, Optik 69(1), 41 (1984).
4. X. Jiang, Q. Lin, and S. Wang, Optik 97(1), 41 (1994).
5. A. Arimoto, Optica Acta 23(3), 245 (1976).