Churn., patent, May 25, 1909; (https://texashistory.unt.edu/ark:/67531/metapth508708/m1/1/: accessed June 20, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu.; .
Churn., patent, May 25, 1909; (https://texashistory.unt.edu/ark:/67531/metapth508708/m1/1/: accessed June 20, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu.; .