Cotton-Chopper, patent, February 28, 1919; (https://texashistory.unt.edu/ark:/67531/metapth1259406/m1/1/: accessed July 18, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu.; .
Cotton-Chopper, patent, February 28, 1919; (https://texashistory.unt.edu/ark:/67531/metapth1259406/m1/1/: accessed July 18, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu.; .