Gopher Trap., patent, July 5, 1881; (https://texashistory.unt.edu/ark:/67531/metapth170192/m1/1/: accessed July 7, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu.; .
Gopher Trap., patent, July 5, 1881; (https://texashistory.unt.edu/ark:/67531/metapth170192/m1/1/: accessed July 7, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu.; .