Blackshear, A. H., Jr. [Letter from A. H. Blackshear, Jr. to Frances O. Ullman, February 26, 1957], letter, February 26, 1957; (https://texashistory.unt.edu/ark:/67531/metapth1472469/m1/1/: accessed July 16, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu.; .