1. R. P. Feynman and A. R. Hibbs,Quantum Mechanics and Path Integrals (McGraw-Hill, New York, 1965).
2. R. P. Feynman,Statistical Mechanics (Benjamin, Reading, Massachusets, 1972).
3. N. N. Bogolubov, “On the New Form of Adiabatic Perturbation Theory in the Problem of Interaction of Particle with Quantum Field,”Ukr. Mat. Zh.
11(2), (1950).
4. N. N. Bogolubov and N. N. Bogolubov, Jr.,Fiz. Elem. Chastits At. Yadra
11(2), (1980).
5. N. N. Bogolubov, Jr. and B. I. Sadovnikov,Zh. Eksp. Teor. Fiz.
13(8), (1962).