[Letter from R. Osthoff to Reverend J. W. Behnken, May 2, 1929], letter, May 2, 1929; (https://texashistory.unt.edu/ark:/67531/metapth606330/m1/1/: accessed June 22, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu; .