1. Encycl. Math. Sci.;V. I. Arnold,2006
2. N. N. Bogolyubov, On Some Statistical Methods in Mathematical Physics (Akad. Nauk Ukr. SSR, Kiev, 1945) [in Russian].
3. N. N. Bogolyubov, “Perturbation theory in nonlinear mechanics,” in Collected Papers Inst. Struct. Mech., Acad. Sci. Ukr. SSR (Akad. Nauk Ukr. SSR, Kiev, 1950), Vol. 14, pp. 9–34 [in Russian].
4. N. N. Bogoliubov and Yu. A. Mitropolski, Asymptotic Methods in the Theory of Non-Linear Oscillations, 3rd ed. (Nauka, Moscow, 1963). Engl. transl. of the 2nd ed.: Asymptotic Methods in the Theory of Non-Linear Oscillations (Gordon and Breach, New York, 1961).
5. Lect. Notes Pure Appl. Math.;V. Burd,2007