Sellers, Harvey Lee; Conyngton, Hugh Ronald & Conyngton, Thomas.Method of and Apparatus for Treating Mineral Pitch.,
patent,
November 5, 1895;
[Washington D.C.].
(https://texashistory.unt.edu/ark:/67531/metapth174131/m1/1/:
accessed June 23, 2024),
University of North Texas Libraries, The Portal to Texas History, https://texashistory.unt.edu;
crediting UNT Libraries Government Documents Department.