[Report to W. P. Gannaway by F. A. Hellinghausen and P. M. Parks, February 12, 1964 #2], report, February 12, 1964; (https://texashistory.unt.edu/ark:/67531/metapth338291/m1/1/: accessed June 25, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu.; .