Geometrical Instrument, patent, March 26, 1918; (https://texashistory.unt.edu/ark:/67531/metapth1257026/m1/2/: accessed July 4, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu.; .
Geometrical Instrument, patent, March 26, 1918; (https://texashistory.unt.edu/ark:/67531/metapth1257026/m1/2/: accessed July 4, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu.; .