1. Tarsinirco, M., Taylor, D., Walker, Ph., et al., Carbon, 1983, vol. 21, p. 69.
2. Centeno, T. and Fuertes, A.B., Carbon, 2000, vol. 38, p. 1067.
3. Berlin, A.A., Geiderikh, M.A., Davydov, B.E., et al., Khimiya polisopryazhennykh system (The Chemistry of Polyconjugated Systems), Moscow: Khimiya, 1972.
4. Kryazhev, Yu.G., Bukalov, S.S., Drozdov, V.A., and Likholobov, V.A., Zh. Fiz. Khim., 2007, vol. 81, no. 3, p. 1.
5. Berlin, A.A., Aseeva, R.M., Kalyaev, G.I., et al., Dokl. Akad. Nauk SSSR, 1962, vol. 144, p. 1042.