Author
United States,
27
Canada,
25
United States. Department of State,
25
United States. Department of State
22
Canada
18
SpringerLink (Online service)
4
Australia,
3
Great Britain,
3
U.S. Fish and Wildlife Service
3
United States
3
Canadian Wildlife Service
2
Denmark,
2
Johnson, Warren T.
2
Lyon, Howard H.
2
Mexico,
2
New Zealand,
2
Norway,
2
Sinclair, Wayne A., 1936-
2
Sweden,
2
United States. Department of State. Bureau of Western Hemisphere Affairs
2
United States. Forest Service
2
Albers, M. A.
1
Alternative Farming Systems Information Center (U.S.)
1
American Society of Agronomy
1
Berryman, John
1
Buse, Lisa J. 1962-
1
Canada Soil Survey Committee
1
Castle, David, 1967-
1
Chicago Botanic Garden
1
Clayton, J. S.
1
Crockett, Lawrence J.
1
Culver, Keith, 1969-
1
Dix, M. E.
1
Dos Passos, Cyril F. 1887-1986
1
EBSCOhost
1
Field, William D., 1914-1992
1
Finkeldey, Reiner
1
Finland,
1
Gates, Galen
1
Giles, F. A.
1
Hattemer, H. H.
1
Holden Arboretum
1
Iceland,
1
Italy,
1
Katovich, Steven A.
1
Knittle, C. Edward
1
Lowry, William R. 1953-
1
Lyon, Howard H.,
1
Maini, J. S.
1
Margolis, L.
1
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