United States. Office of Experiment Stations. General Index to Experiment Station Record, Volumes 71 to 80, 1934-1939, book, July 1949; (https://digital.library.unt.edu/ark:/67531/metadc5054/m1/1/: accessed June 17, 2024), University of North Texas Libraries, UNT Digital Library, digital.library.unt.edu; .