Thompson, F. L.; Peck, W. C. & Beard, A. P. Air conditions close to the ground and the effect on airplane landings, report, April 3, 1934; (https://digital.library.unt.edu/ark:/67531/metadc66146/m1/1/: accessed April 25, 2019), University of North Texas Libraries, Digital Library, digital.library.unt.edu; .