Yeager, Richard A.; Beheim, Milton A. & Klann, John L. Performance of Twin-Duct Variable-Geometry Side Inlets at Mach Numbers of 1.5 to 2.0, report, January 21, 1957; (https://digital.library.unt.edu/ark:/67531/metadc52996/m1/1/: accessed May 26, 2019), University of North Texas Libraries, Digital Library, digital.library.unt.edu; .