1. H. A. Bethe, Handbuch der Physik B1, 24/1: Quantenmechanik der Ein-und Zwei-Electronenprobleme (Berlin, 1933; ONTI, Moscow, 1935).
2. J. S. Slater, Electronic Structure of Molecules (McGraw-Hill, New York, 1963).
3. I. V. Komarov, L. I. Ponomarev, and S. Yu. Slavyanov, Spheroidal and Coulomb Spheroidal Functions (Nauka, Moscow, 1976).
4. S. S. Gershtein and Ya. B. Zeldovich, Zh. Éksp. Teor. Fiz. 57, 654 (1969) [Sov. Phys. JETP 30, 358 (1969)]
5. V. S. Popov, Yad. Fiz. 14, 458 (1971) [Sov. J. Nucl. Phys. 14, 257 (1971)].