Gaertner, H. C. [Letter from H. C. Gaertner to R. Osthoff, October 22, 1927], letter, October 22, 1927; (https://texashistory.unt.edu/ark:/67531/metapth606319/m1/1/: accessed April 16, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu; .