Lovell, Powell M., Jr.; Bates, William R. & Smith, Charles C., Jr. Dynamic Stability and Control Characteristics of a Delta-Wing Vertically Rising Airplane Model in Take-Offs, Landings, and Hovering Flight, report, October 9, 1951; (https://digital.library.unt.edu/ark:/67531/metadc59023/m1/1/: accessed May 3, 2024), University of North Texas Libraries, UNT Digital Library, digital.library.unt.edu; .