1. B. R. Holstein, Comments Nucl. Part. Phys, A19, 221–238 (1990).
2. M. A. Ivanov and T. Mizutani, Phys. Rev., D45, 1580–1601 (1992).
3. M. V. Terent’ev, Yad. Fiz., 16, 162–173 (1972).
4. V. A. Petrun’kin, Fiz. Elem. Chastits At. Yadra, 12, 692–753 (1981).
5. G. Dattoli, G. Matone, and D. Prosperi, Nuovo Cimento Lett., 19, 601–614 (1977).