APA (7th ed.) Citation

Smirnov, M. M., & Wils, W. I. M. (1966). Problems on the equations of mathematical physics. Noordhoff.

Chicago Style (17th ed.) Citation

Smirnov, M. M., and W. I. M. Wils. Problems on the Equations of Mathematical Physics. Groningen: Noordhoff, 1966.

MLA (8th ed.) Citation

Smirnov, M. M., and W. I. M. Wils. Problems on the Equations of Mathematical Physics. Noordhoff, 1966.