Behnken, J. W. [Letter from J. W. Behnken to R. Osthoff, November 2, 1927], letter, November 2, 1927; (https://texashistory.unt.edu/ark:/67531/metapth606582/m1/1/: accessed July 16, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu; .