Lord, Douglas R. Longitudinal stability investigation of a vertical-take-off-and-landing airplane configuration with simulated jet intake and exhaust at Mach numbers of 1.61 and 2.01, report, January 30, 1958; (https://digital.library.unt.edu/ark:/67531/metadc64021/m1/1/: accessed December 19, 2018), University of North Texas Libraries, Digital Library, digital.library.unt.edu; .