Mantzel, Ernest A. [Letter Heading, E. A. Mantzel to W. H. Louviere, February 10, 1954], text, February 10, 1954; (https://texashistory.unt.edu/ark:/67531/metapth1134412/m1/1/: accessed July 9, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu.; .