Charles Wendell Carlson / Cleon J. Mankin / Daryll E. Ray / Denton E. Morrison / Gerald Smith Harshfield / Gerald Thorne / Harry Charles Severin / Henry Herbert DeLong / Herbert R. Allen / John Timothy Slykhuis / Oscar Edward Olson / Ottar Nervik / Quentin S. Kingsley / Robert Wayne Seerley / S. Ray Schultz / Vernon Miles Kirk / Gladstone Albert Kristjanson / Rex David Helfinstine

OCLC:1658433

Alfalfa as feed

Cecilia Schuck / George G. Judge / Howard M. Sauer / Joseph Havlicek / P. D. Evenson / Philip W. Van Vlack / Ray F. Pengra / Rex David Helfinstine / Robert Leroy Rizek / Margaret Talcott Boedeker / Burness G. Wenberg

OCLC:15741850

Agriculture

Rex David Helfinstine

UCAL:C2932951

Agriculture

Rex David Helfinstine

OCLC:958937972

Dry farming

Ray Fremont Pengra / Rex David Helfinstine

CHI:17438054

Crop yields

Rex D. Helfinstine

OCLC:9769657

Farm management

Rex David Helfinstine / South Dakota Agricultural Experiment Station

OCLC:811353776

Land use

Rex David Helfinstine

OCLC:19708138

Dry farming