Porsche Club of America. Maverick Region. Slipstream, Volume 25, Number 1, January 1987, periodical, January 1987; (https://texashistory.unt.edu/ark:/67531/metapth901435/m1/1/: accessed July 11, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu.; .