1. R. W. E. van de Kruijs, M. Th. Rekveldt, H. Fredrikze, et al., Phys. Rev. B 65, 064440 (2002).
2. D. E. Bürgler, M. Buchmeier, S. Gramm, et al., J. Phys.: Condens. Matter 15, S443 (2003).
3. R. R. Gareev, D. E. Bürgler, M. Buchmeier, et al., Phys. Rev. Lett. 87, 157202 (2001).
4. M. V. Gomoyunova, D. E. Malygin, and I. I. Pronin, Fiz. Tverd. Tela (St. Petersburg) 48, 1898 (2006) [Phys. Solid State 48, 2016 (2006)].
5. V. G. Lifshits and Yu. V. Lunyakov, Electron Energy Loss Spectra of Surface Phases on Silicon (Dal’nauka, Vladivostok, 2004) [in Russian].