Cita APA (7a ed.)

Ptolemaeus, C., Kopernik, M., & Kepler, J. (1994). The almagest (2nd ed., 5th print.). Encyclopædia Britannica.

Cita Chicago Style (17a ed.)

Ptolemaeus, Claudius, Mikołaj Kopernik, y Johannes Kepler. The Almagest. 2nd ed., 5th print. Chicago [etc.]: Encyclopædia Britannica, 1994.

Cita MLA (9a ed.)

Ptolemaeus, Claudius, et al. The Almagest. 2nd ed., 5th print. Encyclopædia Britannica, 1994.