[1] Margaret et al., Phys. Rev. A, 1983; 28(1): 332
[2] Wang Y K et al., Phys. Rev. A, 1973; 8(2): 873
[3] MoCall S L. IEEE J. Quant. Electr., 198.5; QE-21 (9): 1441
[5] Naducoi Μ et al. Phys. Rev. A, 1977; 16 (4): 1665
[6] Chandrasker S. Rev. Mod. Phys., 1943; 15: 1