1. N. M. Krylov and N. N. Bogolyubov,Investigation of Longitudinal Stability of an Airplane [in Russian], Gosaviaavtotraktizdat, Moscow-Leningrad (1932).
2. N. M. Krylov and N. N. Bogolyubov,On Oscillations of Synchronous Machines. 2.On Stability of Parallel Work of n-Synchronous Machines [in Russian], Energovydav, Khar'kov (1932).
3. N. N. Bogolyubov,New Methods of Solving Some Mathematical Problems in Engineering [in Russian], Budvydav, Khar'kov (1933).
4. N. M. Krylov and N. N. Bogolyubov,New Methods of Nonlinear Mechanics and Their Application to the Study of Work of Electronic Generators [in Russian], Vol. 1, Gostekhteoretizdat, Moscow-Leningrad (1934).
5. N. M. Krylov and N. N. Bogolyubov,The Application of Methods of Nonlinear Mechanics in the Theory of Stationary Oscillations [in Russian], Izd. VUAN, Kiev (1934).