Cite

A Polar map of part of the northern hemisphere from the latitude of 40 degrees to the Pole.

MLA

A Polar Map of Part of the Northern Hemisphere from the Latitude of 40 Degrees to the Pole. 0AD. https://collections.library.yale.edu/catalog/15234667.

APA, 6th edition

A Polar map of part of the northern hemisphere from the latitude of 40 degrees to the Pole. (0 C.E.). [Maps]. https://collections.library.yale.edu/catalog/15234667.