Lundquist, Eugene E. Comparison of Three Methods for Calculating the Compressive Strength of Flat and Slightly Curved Sheet and Stiffener Combinations, report, March 1933; (https://digital.library.unt.edu/ark:/67531/metadc54181/m1/1/: accessed December 10, 2018), University of North Texas Libraries, Digital Library, digital.library.unt.edu; .