Hydraulic Pressure and Time Indicator, patent, December 24, 1918; (https://texashistory.unt.edu/ark:/67531/metapth1256535/m1/1/: accessed June 22, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu.; .
Hydraulic Pressure and Time Indicator, patent, December 24, 1918; (https://texashistory.unt.edu/ark:/67531/metapth1256535/m1/1/: accessed June 22, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu.; .