MLA

United States. Office of Strategic Services. Reproduction Branch, United States. Office of Strategic Services. Research, and Analysis Branch. The European Fronts [Cartographic Material] : Week Ending 9 January / R & A, OSS. Lithographed in the Reproduction Branch, OSS, 1945. https://collections.library.yale.edu/catalog/15238387.

APA, 6th edition

United States. Office of Strategic Services. Reproduction Branch, U. S. O. of S. S. R., & Branch, A. (1945). The European fronts [cartographic material] : week ending 9 January / R & A, OSS. [Maps, Military maps]. Lithographed in the Reproduction Branch, OSS, https://collections.library.yale.edu/catalog/15238387.