Safety-Casing Clamp, patent, March 15, 1921; (https://texashistory.unt.edu/ark:/67531/metapth1257129/m1/1/: accessed July 6, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu.; .
Safety-Casing Clamp, patent, March 15, 1921; (https://texashistory.unt.edu/ark:/67531/metapth1257129/m1/1/: accessed July 6, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu.; .