Automatic Train-Stop., patent, April 20, 1915; (https://texashistory.unt.edu/ark:/67531/metapth859981/m1/1/: accessed June 11, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu; .
Automatic Train-Stop., patent, April 20, 1915; (https://texashistory.unt.edu/ark:/67531/metapth859981/m1/1/: accessed June 11, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu; .