1. G. V. Domogatsky, V. I. Kopeikin, L. A. Mikaelyan, and V. V. Sinev, Yad. Fiz. 68, 70 (2005) [Phys. At. Nucl. 68, 69 (2005)]; hep-ph/0401221.
2. G. V. Domogatsky, V. I. Kopeikin, L. A. Mikaelyan, and V. V. Sinev, Yad. Fiz. 68, 259 (2005) [Phys. At. Nucl. 68, 234 (2005)]; hep-ph/0403155.
3. G. V. Domogatsky, V. I. Kopeikin, L. A. Mikaelyan, and V. V. Sinev, Yad. Fiz. 69, 46 (2006) [Phys. At. Nucl. 69, 43 (2006)]; hep-ph/0409069.
4. G. V. Domogatsky, V. I. Kopeikin, L. A. Mikaelyan, and V. V. Sinev, Yad. Fiz. 69, 1933 (2006) [Phys. At. Nucl. 69, 1894 (2006)]; hep-ph/0411163.
5. Ya. B. Zel’dovich and O. Kh. Guseĭnov, Dokl. Akad. Nauk SSSR 162, 791 (1965) [Sov. Phys. Dokl. 10, 524 (1965)].