APA

Sommerfeld A., . (1950). Lectures on Theoretical Physics. New York: Academic Press.

Chicago

Sommerfeld A, . 1950. Lectures on Theoretical Physics. New York: Academic Press.

Harvard

Sommerfeld A., . (1950). Lectures on Theoretical Physics. New York: Academic Press.

MLA

Sommerfeld A, . Lectures on Theoretical Physics. New York: Academic Press. 1950.