APA (7th ed.) Citation

Ptolemy, a. 2. c., & Wallis, J. (1682). Harmonicorum libri tres. E Theatro Sheldoniano.

Chicago Style (17th ed.) Citation

Ptolemy, active 2nd century, and John Wallis. Harmonicorum Libri Tres. Oxonii: E Theatro Sheldoniano, 1682.

MLA (9th ed.) Citation

Ptolemy, active 2nd century, and John Wallis. Harmonicorum Libri Tres. E Theatro Sheldoniano, 1682.

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