Cita APA (7a ed.)

Friedman, A. (1982). Variational principles and free-boundary problems. Wiley.

Cita Chicago Style (17a ed.)

Friedman, Avner. Variational Principles and Free-boundary Problems. New York: Wiley, 1982.

Cita MLA (8a ed.)

Friedman, Avner. Variational Principles and Free-boundary Problems. Wiley, 1982.