by Knudson Douglas M
Year of Publication 1979

by Knudson, Douglas M, Cable, Ted T, Beck, Larry
Year of Publication 1995

by Weis, Charles N., Knudson, Douglas M.
Published in The Journal of environmental education (01.07.1980)

by Cable, Ted T., Knudson, Douglas M., Stewart, David J.
Published in The Journal of environmental education (01.01.1984)

by Reyburn, Jerry H., Knudson, Douglas M.
Published in The Journal of environmental education (01.12.1975)

by Knudson, Douglas M
Year of Publication 1976

by Knudson, Douglas M
Year of Publication 1977

by Knudson D.M, Curry E.B
Published in Journal of forestry (01.02.1981)

by Caneday, Lowell
Published in Journal of Leisure Research (22.06.1996)

by Reyburn, Jerry H, Knudson, Douglas M
Published in Journal of Environmental Education (1975)

by Chaney, W.R, Knudson, D.M
Published in International tree crops journal (1988)

by Degler, George Fredrick, Knudson, Douglas M
Year of Publication 1972

by Callahan, John Conrad, Knudson, Douglas M
Year of Publication 1966

by Knudson D.M, Larson G.B
Published in Journal of forestry (01.01.1982)