Gildersleeve, Fred E. & Trice, William L. Film Actuating Mechanism For Motion Picture Cameras., patent, May 12, 1917; (https://texashistory.unt.edu/ark:/67531/metapth1256856/m1/1/: accessed July 17, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu; .