Hoefer, Charle,s Jr.; Belt, Marcus L., Jr. & Belt, William R.Churn,
patent,
May 19, 1913;
[Washington D.C.].
(https://texashistory.unt.edu/ark:/67531/metapth853896/m1/1/:
accessed June 11, 2024),
University of North Texas Libraries, The Portal to Texas History, https://texashistory.unt.edu;
crediting UNT Libraries Government Documents Department.