Telephone-Transmitter., patent, May 11, 1897; (https://texashistory.unt.edu/ark:/67531/metapth174611/m1/1/: accessed June 22, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu.; .
Telephone-Transmitter., patent, May 11, 1897; (https://texashistory.unt.edu/ark:/67531/metapth174611/m1/1/: accessed June 22, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu.; .