The National geographic magazine map of the new Balkan states and central Europe [cartographic material] / prepared by J.G. Bartholomew ; Gilbert H. Grosvenor, editor.
MLA
Bartholomew, J. G. (John George), 1860-1920, National Geographic Society (U.S.). The National geographic magazine map of the new Balkan states and central Europe [cartographic material] / prepared by J.G. Bartholomew ; Gilbert H. Grosvenor, editor.. BRBL_00256. [1914]. https://collections.library.yale.edu/catalog/15498757.
APA, 6th edition
Bartholomew, J. G. (John George), 1860-1920, & National Geographic Society (U.S.). (["BRBL_00256"])([1914])[The National geographic magazine map of the new Balkan states and central Europe [cartographic material] / prepared by J.G. Bartholomew ; Gilbert H. Grosvenor, editor.]. https://collections.library.yale.edu/catalog/15498757.