Συγγραφέας
Colorado Agricultural College. Extension Service
58
Colorado A & M College. Extension Service
21
Colorado State College (Fort Collins, Colo.). Extension Service
16
Iowa State University. Cooperative Extension Service
3
Iowa State University. Agricultural and Home Economics Experiment Station
2
New Mexico State University of Agriculture, Engineering, and Science. Agricultural Extension Service
2
New Mexico State University of Agriculture, Engineering, and Science. Cooperative Extension Service
2
Purdue University. Department of Agricultural Extension
2
United States. Department of Agriculture
2
Indonesia. Badan Pendidikan, Latihan dan Penyuluhan Pertanian
1
Iowa Agriculture and Home Economics Experiment Station
1
Iowa State College. Agricultural Experiment Station
1
Iowa State College. Agricultural Extension Service
1
Iowa State College. Agricultural and Home Economics Experiment Station
1
Iowa State College. Cooperative Extension Service
1
Minnesota Extension Service
1
New Mexico College of Agriculture and Mechanic Arts. Agricultural Extension Service
1
New Mexico State University. Cooperative Extension Service
1
New Mexico. College of Agriculture and Mechanic Arts, State College. Agricultural Extension Service
1
Ohio State University. Cooperative Extension Service
1
Ohio State University. Department of Agricultural Economics and Rural Sociology
1
Purdue University. Agricultural Experiment Station
1
Purdue University. Agricultural Extension Service
1
South Dakota State University. Cooperative Extension Service
1
Texas Agricultural Extension Service
1
United States. Federal Extension Service
1
United States. National Archives and Records Service
1
University of Arkansas (System). Cooperative Extension Service
1
University of Minnesota. Agricultural Extension Service
1