Air University (U.S.). Extension Course Institute. [USAF Extension Course Shipping List February 9, 1965], text, February 9, 1965; (https://texashistory.unt.edu/ark:/67531/metapth1010240/m1/1/: accessed June 28, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu; .