Journal of agricultural research - Association of American Agricultural Colleges; Experiment Stations. (U.S. Govt. Printing Office, 1920)

Journal of agricultural research - Association of American Agricultural Colleges; Experiment Stations. (U.S. Govt. Printing Office, 1921)

Journal of agricultural research - Association of American Agricultural Colleges; Experiment Stations. (U.S. Govt. Printing Office, 1923)