Contributor
- Colorado Agricultural Experiment Station (21)
- Naftalin, Arthur (5)
- University of Minnesota Duluth (4)
- International Institute of San Francisco (3)
- Sanders, Stuart (Producer) (2)
- Anderson, Wendell (1)
- Balduf, Carl (1)
- Cary, Kate (1)
- Diles, Dave (1)
- Eastern Rhode Island Conservation District (1)
- Geological Survey (U.S.) (1)
- Gray, Cornelia (1)
- Northwestern National Bank of Minneapolis (Minn.) (1)
- Pauco, Jozef (1)
- Prokupek, Milan (1)
- Quie, Albert H. (1)
- Watson, Marion (1)
- Williams, George (1)
