Geiger, Robert M. [Letter from Robert M. Geiger to Elisa de La Vara - 1975-04-30], letter, April 30, 1975; (https://texashistory.unt.edu/ark:/67531/metapth251262/m1/1/: accessed April 30, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu; .