Mayo, Wilbur L. Hydrodynamic impact of a system with a single elastic mode I : theory and generalized solution with an application to an elastic airframe, report, January 1, 1952; (https://digital.library.unt.edu/ark:/67531/metadc60433/m1/1/: accessed November 24, 2017), University of North Texas Libraries, Digital Library, digital.library.unt.edu; .