by National University Extension Association. Conference

1927

by National University Extension Association

1922

by University of Wisconsin. College of Agriculture

1918

by University of Florida

1929

by University of Michigan

1935

by University of North Carolina (1793-1962)

1926

by University of Wisconsin. Agricultural Experiment Station

1913

by University of Wisconsin. Agricultural Experiment Station

1911

by Purdue University. Department of Agricultural Extension

1921

by University of the State of New York

1913

by University of the State of New York

1913

by University of Wyoming. Agricultural Extension Service

1915