APA (7th ed.) Citation

Blanchard, P., & Brüning, E. (1992). Variational methods in mathematical physics: A unified approach. Springer.

Chicago Style (17th ed.) Citation

Blanchard, Philippe, and Erwin Brüning. Variational Methods in Mathematical Physics: A Unified Approach. Berlin u.a: Springer, 1992.

MLA (9th ed.) Citation

Blanchard, Philippe, and Erwin Brüning. Variational Methods in Mathematical Physics: A Unified Approach. Springer, 1992.