1. M. Hargittai, Coord. Chem. Rev., 91, 35–88 (1998).
2. G. V. Girichev, T. G. Danilova, N. I. Giricheva, K. S. Krasnov, et al., Izv. Vyssh. Uchebn. Zaved., Khim. Khim. Tekhnol., 21, No. 5, 627–629 (1978).
3. E. Z. Zasorin, Zh. Fiz. Khim., 62, No. 4, 883–895 (1988).
4. A. Kovács and R. J. M. Konings, Vibr. Spectrosc., 15, 131–135 (1997).
5. P. C. Groen (to be published).