1. A. Sammar and J.-M. Andre, Opt. Commun. 149, 348 (1998).
2. Ya. I. Nesterets and V. I. Punegov, Kristallografiya 44, 980 (1999) [Crystallogr. Rep. 44, 913 (1999)].
3. B. M. Clemens and J. G. Gay, Phys. Rev. B 35, 9337 (1987).
4. A. V. Andreev and I. R. Prudnikov, Surf. Investig. 12, 421 (1997).
5. V. I. Punegov, Poverkhnost’: Rentgenovskie, Sinkhrotronnye, Ne $$\overset{\lower0.5em\hbox{$\smash{\scriptscriptstyle\smile}$}}{l} $$ tronnye Issled., No. 2, 19 (2003).