The Balkans [cartographic material] : Albania, Bulgaria, Greece and Yugoslavia.
MLA
of State. Interim Research, United States. Dept., and Intelligence Service. The Balkans [Cartographic Material] : Albania, Bulgaria, Greece and Yugoslavia. IRIS, 1945. https://collections.library.yale.edu/catalog/15498774.
APA, 6th edition
of State. Interim Research, U. S. D., & Service, I. (1945). The Balkans [cartographic material] : Albania, Bulgaria, Greece and Yugoslavia. [Maps]. IRIS, https://collections.library.yale.edu/catalog/15498774.