MLA

of Strategic Services. Research, United States. Office, and Analysis Branch. The European Fronts [Cartographic Material] : Approximate Areas of Present Occupation -- Week Ending 15 May. Reproduction Branch, OSS, 0AD. https://collections.library.yale.edu/catalog/15238396.

APA, 6th edition

of Strategic Services. Research, U. S. O., & Branch, A. (0 C.E.). The European fronts [cartographic material] : approximate areas of present occupation -- week ending 15 May. [Maps]. Reproduction Branch, OSS, https://collections.library.yale.edu/catalog/15238396.