MLA

of Strategic Services, United States. Office. Belgium Generation and Transmission of Electrical Energy / Compiled and Drawn in Geography Division, O.S.S. Office of Strategic Services, Reproduction Branch, 1942. https://collections.library.yale.edu/catalog/15352340.

APA, 6th edition

of Strategic Services, U. S. O. (1942). Belgium Generation and Transmission of Electrical Energy / compiled and drawn in Geography Division, O.S.S. [Maps]. Office of Strategic Services, Reproduction Branch, https://collections.library.yale.edu/catalog/15352340.