Shanklin, J. Gordon. [Letter from J. Gordon Shanklin, April 27, 1964], legal document, April 27, 1964; (https://texashistory.unt.edu/ark:/67531/metapth337427/m1/1/: accessed July 1, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu.; .