[Letter from Isaac H. Kempner to Mr. and Mrs. Scharpwinkel, December 24, 1956], letter, December 24, 1956; (https://texashistory.unt.edu/ark:/67531/metapth1512520/m1/1/: accessed June 30, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu.; .