APA (7th ed.) Citation

Rektorys, K. (1980). Variational methods in mathematics, science, and engineering (2nd ed.). D. Reidel Pub. Co..

Chicago Style (17th ed.) Citation

Rektorys, Karel. Variational Methods in Mathematics, Science, and Engineering. 2nd ed. Dordrecht, Holland ; Boston, U.S.A.: D. Reidel Pub. Co., 1980.

MLA (8th ed.) Citation

Rektorys, Karel. Variational Methods in Mathematics, Science, and Engineering. 2nd ed. D. Reidel Pub. Co., 1980.