[Letter from Isaac H. Kempner to Mr. Harris L. Kempner, October 9, 1956], letter, October 9, 1956; (https://texashistory.unt.edu/ark:/67531/metapth1419161/m1/1/: accessed July 11, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu.; .