Santos, Ray E. [Letter from Ray E. Santos to John J. Herrera - 1977-05-04], letter, May 4, 1977; (https://texashistory.unt.edu/ark:/67531/metapth249843/m1/1/: accessed July 3, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu; .