Automatic Train Stop, patent, December 26, 1916; (https://texashistory.unt.edu/ark:/67531/metapth858615/m1/1/: accessed June 20, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu.; .
Automatic Train Stop, patent, December 26, 1916; (https://texashistory.unt.edu/ark:/67531/metapth858615/m1/1/: accessed June 20, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu.; .