Alpert, Arthur M. [Letter from Arthur M. Alpert to Department of State, May 11, 1959], letter, May 11, 1959; (https://texashistory.unt.edu/ark:/67531/metapth1412481/m1/1/: accessed July 17, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu; .