Cite

Phases of the fixed stars, book II.

MLA

Ptolemy, active 2nd century. Phases of the fixed stars, book II.. [between 1500 and 1600]. https://collections.library.yale.edu/catalog/11007487.

APA, 6th edition

Ptolemy, active 2nd century. ([between 1500 and 1600])[Phases of the fixed stars, book II.]. https://collections.library.yale.edu/catalog/11007487.