Butt, Harlan W. [Letter from Harlan W. Butt to Nancy Walkup, April 16, 1996], letter, April 16, 1996; (https://texashistory.unt.edu/ark:/67531/metadc1824159/m1/1/: accessed July 6, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu.; .