Hackney, D. R. [Letter from D. R. Hackney to C. C. Cox, December 27, 1912], letter, December 27, 1912; (https://texashistory.unt.edu/ark:/67531/metapth1243426/m1/1/: accessed July 10, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu.; .