Alpert, Arthur M. [Letter from Edward R. Thompson, Jr. to Arthur M. Alpert, October 20, 1965], letter, October 10, 1965; (https://texashistory.unt.edu/ark:/67531/metapth1325444/m1/1/: accessed April 27, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu; .