[Copy of Letter from William M. Nathan to Dr. Hyman J. Ettlinger, December 18, 1945], letter, December 18, 1945; (https://texashistory.unt.edu/ark:/67531/metapth1485648/m1/1/: accessed July 18, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu; .