1. A. Bohr, B. Mottelson, D. Pines, Phys. Rev. 110, 936 (1958).
2. S. T. Belyaev, K. Dan, Vidensk. Selsk. Mat. Fys. Medd. 31, 11 (1959).
3. N. N. Bogolyubov, Dokl. Akad. Nauk SSSR 119, 52 (1958) [Sov. Phys. Doklady 3, 279 (1958)].
4. V. G. Solov’ev, Zh. Éksp. Teor. Fiz. 35, 823 (1958) [Sov. Phys. JETP 8, 572 (1959)]; 36, 1869 (1959) [9, 1325 (1959)]; Nucl. Phys. 9, 655 (1958).
5. V. G. Solov’ev, Effect of Pair Correlations of the Superconducting Type on the Properties of Atomic Nuclei [in Russian], Atomizdat, Moscow (1963).