Cite

Hammond's large scale war map of the Western Front [cartographic material].

MLA

Hammond, C. S., and Company. Hammond's Large Scale War Map of the Western Front [Cartographic Material]. C.S. Hammond, 0AD. https://collections.library.yale.edu/catalog/15824481.

APA, 6th edition

Hammond, C. S., & C. (0 C.E.). Hammond's large scale war map of the Western Front [cartographic material]. [Military maps]. C.S. Hammond, https://collections.library.yale.edu/catalog/15824481.