MLA

of Strategic Services. Research, United States. Office, and Analysis Branch. Belgian Congo, Roads, Railroads and Navigable Waterways / Drawn in the Branch of Research and Analysis, OSS. OSS, 1943. https://collections.library.yale.edu/catalog/15533530.

APA, 6th edition

of Strategic Services. Research, U. S. O., & Branch, A. (1943). Belgian Congo, roads, railroads and navigable waterways / drawn in the Branch of Research and Analysis, OSS. [Maps]. OSS, https://collections.library.yale.edu/catalog/15533530.