Cite

Letts's General Map of Russia & Turkey.

MLA

Letts, Son, and Co. Letts's General Map of Russia & Turkey. Letts, Son & Co., 0AD. https://collections.library.yale.edu/catalog/15506438.

APA, 6th edition

Letts, S., & C. (0 C.E.). Letts's General Map of Russia & Turkey. [Maps]. Letts, Son & Co., https://collections.library.yale.edu/catalog/15506438.