Sovereignty and mandate boundary lines in 1921 of the islands of the Pacific / prepared in the Map Department of the National Geographic Society for the National Geographic magazine ; drawn by Albert H. Bumstead and James M. Darley.
MLA
National Geographic Society (U.S.). Map Dept. Sovereignty and mandate boundary lines in 1921 of the islands of the Pacific / prepared in the Map Department of the National Geographic Society for the National Geographic magazine ; drawn by Albert H. Bumstead and James M. Darley.. BRBL_00021. c1921.. https://collections.library.yale.edu/catalog/15824500.
APA, 6th edition
National Geographic Society (U.S.). Map Dept. (["BRBL_00021"])(c1921.)[Sovereignty and mandate boundary lines in 1921 of the islands of the Pacific / prepared in the Map Department of the National Geographic Society for the National Geographic magazine ; drawn by Albert H. Bumstead and James M. Darley.]. https://collections.library.yale.edu/catalog/15824500.