APA (7th ed.) Citation

Becker, M. (1964). The Principles and applications of variational methods. M. I. T. Press.

Chicago Style (17th ed.) Citation

Becker, Martin. The Principles and Applications of Variational Methods. Cambridge, Mass: M. I. T. Press, 1964.

MLA (9th ed.) Citation

Becker, Martin. The Principles and Applications of Variational Methods. M. I. T. Press, 1964.