Heller, Mark F. [Letter from Mark F. Heller to D. W. Kempner, January 12, 1953], letter, January 12, 1953; (https://texashistory.unt.edu/ark:/67531/metapth1325939/m1/1/: accessed July 6, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu.; .