Experiment Station Record, Volume 81, July-December, 1939, book, 1940; (https://digital.library.unt.edu/ark:/67531/metadc5075/m1/1/: accessed July 16, 2024), University of North Texas Libraries, UNT Digital Library, digital.library.unt.edu; .
Experiment Station Record, Volume 81, July-December, 1939, book, 1940; (https://digital.library.unt.edu/ark:/67531/metadc5075/m1/1/: accessed July 16, 2024), University of North Texas Libraries, UNT Digital Library, digital.library.unt.edu; .