1. R. W. Siegel, Nanostruct. Mater. 4, 121 (1994).
2. A. I. Gusev, Usp. Fiz. Nauk 168, 55 (1998) [Phys. Usp. 45, 49 (1998)].
3. O. A. Khasanov, Yu. F. Ivanov, N. A. Popova, et al., Perspekt. Mater., No. 5, 52 (1999).
4. V. V. Ivanov and V. R. Khrustov, Neorg. Mater. 34, 495 (1998).
5. Yu. K. Voron’ko, M. A. Vishnyakova, E. E. Lomonova, et al., Neorg. Mater. 40, 585 (2004).