Cita APA (7th ed.)

Ėl'sgolt͡s, L. (1961). Calculus of variations. Pergamon.

Cita Chicago (17th ed.)

Ėl'sgolt͡s, L.Ė. Calculus of Variations. London: Pergamon, 1961.

Cita MLA (8th ed.)

Ėl'sgolt͡s, L.Ė. Calculus of Variations. Pergamon, 1961.