Hancock, Austin P. [Letter from Austin P. Hancock to Wayne Gibbens, March 20, 1961], letter, March 20, 1961; (https://texashistory.unt.edu/ark:/67531/metapth1272883/m1/1/: accessed May 21, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu; .