National Geographic Society (U.S.). Cartographic Division.
Scale 1:1,765,000. 1 in. = 28 miles ; Albers conic equal-area projection
[Washington, D.C.] : National Geographic Society, [2001]
National Geographic Society (U.S.). Cartographic Division.
1:63,360,000; 1000 miles to the inch at the equator ; Van der Grinten proj. (E100⁰00'--W90⁰00'/N80⁰00' --S80⁰00')
Washington, D.C. : The Society, [1960]