[Letter from O. P. Jackson Seed Company to D. W. Kempner, February 7, 1952], letter, February 7, 1952; (https://texashistory.unt.edu/ark:/67531/metapth1325884/m1/1/: accessed July 17, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu; .