APA (7th ed.) Citation

Ptolemy, a. 2. c., & Robbins, F. E. (1940). Tetrabiblos. Harvard University Press.

Chicago Style (17th ed.) Citation

Ptolemy, active 2nd century, and Frank Egleston Robbins. Tetrabiblos. Cambridge, Mass. : London, W. Heinemann: Harvard University Press, 1940.

MLA (9th ed.) Citation

Ptolemy, active 2nd century, and Frank Egleston Robbins. Tetrabiblos. Harvard University Press, 1940.