United States. Office of Experiment Stations. A Report on the Work and Expenditures of the Agricultural Experiment Stations, June 30, 1915, book, 1917; (https://digital.library.unt.edu/ark:/67531/metadc6010/m1/1/: accessed December 13, 2017), University of North Texas Libraries, Digital Library, digital.library.unt.edu; .