APA (7th ed.) Citation

Sommerfeld, A., & Straus, E. G. (1949). Partial differential equations in physics. Academic Press.

Chicago Style (17th ed.) Citation

Sommerfeld, Arnold, and Ernst G. Straus. Partial Differential Equations in Physics. New York: Academic Press, 1949.

MLA (8th ed.) Citation

Sommerfeld, Arnold, and Ernst G. Straus. Partial Differential Equations in Physics. Academic Press, 1949.