National Geographic Society (U.S.). (2019). The first photograph ever made showing the division between the troposhere and the stratosphere and also the actual curvature of the earth : photographed from an elevation of 72,395 feet, the highest point ever reached by man. National Geographic Society.MLA Citation
National Geographic Society (U.S.). The First Photograph Ever Made Showing the Division between the Troposhere and the Stratosphere and Also the Actual Curvature of the Earth : Photographed From an Elevation of 72,395 Feet, the Highest Point Ever Reached By Man. National Geographic Society, 2019.