Alpert, Arthur M. [Letter from Arthur M. Alpert to Jack Springer, January 11, 1963], letter, January 11, 1963; (https://texashistory.unt.edu/ark:/67531/metapth1289461/m1/1/: accessed July 17, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu.; .