Bogolyubov N. A collection of scientific works in 12 (twelve) volumes. No Volume 7. In Russian (ask us if in doubt)/Bogolyubov N. N. Sobranie nauchnykh trudov v 12 (dvenadtsati) tomakh. Net toma 7. Volume 1: Mathematics and Non-Linear Mechanics: Mathematics (1925-1990). Volume 2: Mathematics and Non-Linear Mechanics: Non-Linear Mechanics (1932-1940). Volume 3: Mathematics and Non-Linear Mechanics: Asymptomatic Methods in the Theory of Non-Linear oscillations. Volume 4: Mathematics and Non-Linear Mechanics: Non-Linear Mechanics (1945-1974). Volume 5: Statistical Mechanics: Non-Equilibrium Statistical Mechanics (1939-1980). Volume 6: Statistical Mechanics: Equilibrium Methods in the Theory of Non-Linear oscillations. Volume 4: Mathematics and Non-Linear Mechanics: Non-Linear Mechanics (1945-1974). Vol. SKUalb85652c3d0bd92f75.