Elsgolts, L., & Yankovsky, G. (1973). Differential equations and the calculus of variations. MIR Publishers.
Chicago Style (17th ed.) CitationElsgolts, L., and George Yankovsky. Differential Equations and the Calculus of Variations. Moscow: MIR Publishers, 1973.
MLA (8th ed.) CitationElsgolts, L., and George Yankovsky. Differential Equations and the Calculus of Variations. MIR Publishers, 1973.
Warning: These citations may not always be 100% accurate.