Kempner, Ruth Alma. [Letter from Ruth Alma Kempner to the Shamrock-Hilton Hotel, May 20, 1964], letter, May 20, 1964; (https://texashistory.unt.edu/ark:/67531/metapth1421001/m1/1/: accessed July 10, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu.; .