MLA

Great Britain. War Office. General Staff. Geographical Section, United States. Army Map Service. Murmansk Railway. Sheet 2. The Service, 0AD. https://collections.library.yale.edu/catalog/15475634.

APA, 6th edition

Great Britain. War Office. General Staff. Geographical Section, U. S. A. M. S. (0 C.E.). Murmansk railway. Sheet 2. [Maps]. The Service, https://collections.library.yale.edu/catalog/15475634.