Nelson, William J. & Ebert, John W., Jr. An Investigation of the Air Flow Around a Martin PBM-3 Flying Boat by Means of Tufts, report, April 1943; (https://digital.library.unt.edu/ark:/67531/metadc60907/m1/1/: accessed April 22, 2024), University of North Texas Libraries, UNT Digital Library, digital.library.unt.edu; .