1. M. K. Tiwari, B. Gowrishankar, V. K. Raghuvanshi, et al., Bull. Mater. Sci. 25, 435 (2002).
2. A. P. Kovtun, V. P. Krasnolutskiĭ, and I. V. Sitnik, http://zhurnal.ape.relarn.ru/articles/2002/190.pdf .
3. E. Filatova, A. Stepanov, C. Blessing, et al., J. Phys.: Condens. Matter 7, 2731 (1995).
4. A. P. Martin, A. N. Brunton, G. W. Fraser, et al., Nucl. Instrum. Methods Phys. Res. A 460, 316 (2001).
5. I. A. Brytov and Yu. N. Romashchenko, Fiz. Tverd. Tela (Leningrad) 20, 664 (1978) [Sov. Phys. Solid State 20, 384 (1978)].