Thomas, Robert Smith; Hardwick, Sauny Warren & Elam, William Erwin. Machine for Handling and Cleaning Seed-Cotton., patent, August 25, 1891; (https://texashistory.unt.edu/ark:/67531/metapth172771/m1/2/: accessed June 23, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu.; .