Johnson, Lyndon B. (Lyndon Baines), 1908-1973. [Letter from Lyndon B. Johnson to Helen Corbitt, April 30, 1971], letter, April 30, 1971; (https://texashistory.unt.edu/ark:/67531/metapth1157559/m1/1/: accessed April 26, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu; .