Improvement in Revolving Conical Mold-Boards, patent, May 22, 1877; (https://texashistory.unt.edu/ark:/67531/metapth166658/m1/1/: accessed July 18, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu; .
Improvement in Revolving Conical Mold-Boards, patent, May 22, 1877; (https://texashistory.unt.edu/ark:/67531/metapth166658/m1/1/: accessed July 18, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu; .