Interchangeable Illuminated Sign., patent, February 14, 1911; (https://texashistory.unt.edu/ark:/67531/metapth508987/m1/1/: accessed June 22, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu.; .
Interchangeable Illuminated Sign., patent, February 14, 1911; (https://texashistory.unt.edu/ark:/67531/metapth508987/m1/1/: accessed June 22, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu.; .