"803301AI (R02112) 5-07." Also shows "10°C (50°F) isotherm, July". North Pole at center. Available also through the Library of Congress Web site as a raster image. Includes note.
United States. Central Intelligence Agency
2007
<a rel="nofollow" class="external free" href="https://www.loc.gov/item/2007630644/">https://www.loc.gov/item/2007630644/</a>