APA (7th ed.) Citation

Ptolemy, a. 2. c., & Wallis, J. (1977). Harmonicorum libri tres. Broude Brothers.

Chicago Style (17th ed.) Citation

Ptolemy, active 2nd century, and John Wallis. Harmonicorum Libri Tres. New York: Broude Brothers, 1977.

MLA (9th ed.) Citation

Ptolemy, active 2nd century, and John Wallis. Harmonicorum Libri Tres. Broude Brothers, 1977.