A geographical and historical guide to the world's wars, 4000 B.C. to 1918 [cartographic material] : No. 1, north-western Europe, showing the "Western Front" / engraved and printed at the Matthews-Northrup Works, Buffalo, N.Y.
MLA
Encyclopaedia Britannica, inc, and Matthews-Northrup Works. A Geographical and Historical Guide to the World's Wars, 4000 B.C. to 1918 [Cartographic Material] : No. 1, North-Western Europe, Showing the "Western Front" / Engraved and Printed at the Matthews-Northrup Works, Buffalo, N.Y. Encylcopaedia Britannica, 1918. https://collections.library.yale.edu/catalog/15237965.
APA, 6th edition
Encyclopaedia Britannica, inc, & Works, M.-N. (1918). A geographical and historical guide to the world's wars, 4000 B.C. to 1918 [cartographic material] : No. 1, north-western Europe, showing the "Western Front" / engraved and printed at the Matthews-Northrup Works, Buffalo, N.Y. [Maps, Military maps]. Encylcopaedia Britannica, https://collections.library.yale.edu/catalog/15237965.
