Roller-Index., patent, January 5, 1892; (https://texashistory.unt.edu/ark:/67531/metapth172906/m1/1/: accessed April 25, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu; .
Roller-Index., patent, January 5, 1892; (https://texashistory.unt.edu/ark:/67531/metapth172906/m1/1/: accessed April 25, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu; .