Drill Bit, patent, January 3, 1922; (https://texashistory.unt.edu/ark:/67531/metapth1259474/m1/1/: accessed July 6, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu.; .
Drill Bit, patent, January 3, 1922; (https://texashistory.unt.edu/ark:/67531/metapth1259474/m1/1/: accessed July 6, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu.; .