1. A. A. Askadskiĭ, Usp. Khim. 68, 349 (1999).
2. A. D. Pomogaĭlo, Usp. Khim. 71, 5 (2002).
3. D. Chemla and G. Zyss, Nonlinear Optical Properties of Organic Molecules and Crystals (Academic, New York, 1987).
4. Conjugated Oligomers, Polymers, and Dendrimers: From Polyacetylene to DNA, Ed. by J. Bredas (De Boeck and Larcier, Brussels, 1999).
5. F. A. Zhuravlev, N. A. Orlova, V. V. Shelkovnikov, A. M. Plekhanov, S. T. Rautian, and V. P. Safonov, Pis’ma Zh. Éksp. Teor. Fiz. 56(5), 264 (1992) [JETP Lett. 56 (5), 260 (1992)].