APA (7th ed.) Citation

Kopff, A. (1923). The Mathematical theory of relativity. E. P. Dutton.

Chicago Style (17th ed.) Citation

Kopff, August. The Mathematical Theory of Relativity. New York: E. P. Dutton, 1923.

MLA (9th ed.) Citation

Kopff, August. The Mathematical Theory of Relativity. E. P. Dutton, 1923.

Warning: These citations may not always be 100% accurate.