Mount Everest (topographic map, second edition), National Geographic Society/Boston Museum of Science/Swiss Foundation for Alpine Research, Bradford Washburn, project director, 1991.
Mount Everest (Topographische Karte, 2. Auflage), National Geographic Society/Boston Museum of Science/Schweizerische Stiftung für Alpine Forschung, Bradford Washburn, Projektleiter, 1991.