Ptolomeo, C., Tolomeo, C., Copernicus, N., Copérnico, N., & Kepler, J. (1952). The almagest. Encyclopaedia Britannica.
Chicago Style (17th ed.) CitationPtolomeo, Claude, Claudio Tolomeo, Nicolaus Copernicus, Nicolás Copérnico, and Johannes Kepler. The Almagest. Chicago: Encyclopaedia Britannica, 1952.
MLA (9th ed.) CitationPtolomeo, Claude, et al. The Almagest. Encyclopaedia Britannica, 1952.