Tomazic, William A. & Kinney, George R. Experimental performance of the mixed-oxides-of-nitrogen-ammonia propellant combination in a 1000-pound-thrust rocket engine, report, March 28, 1955; (https://digital.library.unt.edu/ark:/67531/metadc61181/m1/1/: accessed October 23, 2018), University of North Texas Libraries, Digital Library, digital.library.unt.edu; .