Disk-Harrow Sharpener., patent, November 25, 1913; (https://texashistory.unt.edu/ark:/67531/metapth858390/m1/1/: accessed June 21, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu.; .
Disk-Harrow Sharpener., patent, November 25, 1913; (https://texashistory.unt.edu/ark:/67531/metapth858390/m1/1/: accessed June 21, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu.; .