1. I.V. Komarov, L.I. Ponomarev, S.Yu. Slavyanov, Spheroidal and Coulomb Spheroidal Functions (Nauka, Moscow, 1976) (in Russian)
2. S.K. Luke, G. Hunter, R.P. McFachran, M. Cohen, J. Chem. Phys. 50, 1644 (1969)
3. V.S. Popov, Pis. Zh. Eksp. Teor. Fiz. 11, 254 (1970)
4. V.S. Popov, Yad. Fiz. 12, 429 (1970)
5. V.S. Popov, Zh. Eksp. Teor. Fiz. 59, 965 (1970)