1. F. R. Gantmacher, Lectures in Analytical Mechanics, Mir, Moscow (1975).
2. R. Courant and D. Hilbert, Methods of Mathematical Physics, Vol. 1, Wiley, New York (1989).
3. D. M. Lila, Sufficient Stability Conditions for Nonstationary Large-Scale Mechanical Systems [in Ukrainian], Author’s Abstract of PhD Thesis in Theoretical Mechanics (01.02.01), Kyiv (2009).
4. D. M. Lila, Sufficient Stability Conditions for Nonstationary Large-Scale Mechanical Systems [in Ukrainian], PhD Thesis, Kyiv (2009).
5. I. Z. Shtokalo, “(In)stability criterion for the solutions of linear differential equations with quasi-periodic coefficients,” Mat. Sb., 19 (61), No. 2, 263–286 (1946).