Mobley, Henry Grady. Automatic Air and Gas Relief Valve for Oil-Distributing Systems., patent, May 24, 1921; (https://texashistory.unt.edu/ark:/67531/metapth1259050/m1/2/: accessed July 15, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu; .

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