by University of Missouri--Columbia. Agricultural Experiment Station

1919

by University of Missouri--Columbia. Agricultural Experiment Station

1921

by University of Colorado (Boulder campus)

1921

by Kansas. University, University of Kansas

1925

by University of Kansas

1927

by University of Arizona

1903

by University of Arizona

1903

by University of Nevada

1929

by Harvard University

1910

by Harvard University

1910

by University of California, Berkeley

1923

by University of California (System)

1920