- Oregon State University. Extension Service19
- Oregon Agricultural College. Experiment Station10
- Oregon Agricultural Experiment Station9
- Fisher, Glenn C.6
- Oregon State College. Agricultural Experiment Station5
- Washburn, F. L. (Frederic Leonard), 1860 19275
- Filip, Gregory M.4
- Lovett, A. L. (Arthur Lester), 1885 19244
- Shaw, David Carl, 1955 4
- Stebbins, Robert L.4
- United States. Forest Service. Northern Region. State & Private Forestry4
- Cordley, A. B. (Arthur Burton), 1864 19363
- Macswan, Iain C.3
- Oester, Paul T.3
- Oregon Agricultural College. Extension Service3
- Oregon State College. Federal Cooperative Extension Service3
- Oregon State University. Agricultural Experiment Station3
- Tunnock, Scott3
- United States. Department Of Agriculture3
- University Of Idaho. Cooperative Extension Service3