Leslie, Donald A. [Letter from Donald A. Leslie to R. M. Armstrong, May 14, 1965], letter, May 14, 1965; (https://texashistory.unt.edu/ark:/67531/metapth1209984/m1/1/: accessed April 25, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu; .