Lever., patent, August 6, 1907; (https://texashistory.unt.edu/ark:/67531/metapth510043/m1/1/: accessed June 20, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu.; .
Lever., patent, August 6, 1907; (https://texashistory.unt.edu/ark:/67531/metapth510043/m1/1/: accessed June 20, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu.; .