Marcello, Ronald E. & Allen, Billy. Oral History Interview with Billy Allen, March 1, 1976, book, March 1, 1976; (https://texashistory.unt.edu/ark:/67531/metadc1529118/m1/50/: accessed July 16, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu.; .