Penholder., patent, October 13, 1903; (https://texashistory.unt.edu/ark:/67531/metapth512982/m1/2/: accessed July 6, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu.; .
Penholder., patent, October 13, 1903; (https://texashistory.unt.edu/ark:/67531/metapth512982/m1/2/: accessed July 6, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu.; .