Among the negatives of the famous Norwegian photographer Anders Beer Wilse (1865-1949) at Norsk Folkemuseum (The Norwegian Museum of Cultural History at Bygdøy)
photogravure Air pioneering in the Arctic : the two polar flights of Roald Amundsen and Lincoln Ellsworth / edited and arranged by Howard Eldred Kershner New York : National Americana Society 1929 (70) pl. ill.,fig.,faks.,kart.port. Part 1: The 1925 flight from Spitzbergen to 88 degrees north. Part 2: First crossing of the Polar Sea, 1926