@book{ Solr-ocm39138823, title = {Soil compaction after yarding of small-diameter Douglas-fir with a small tractor in Southwest Oregon}, series = {Research paper PNW-RP}, series = {Research paper PNW}, author = {Amaranthus, Michael P.}, editor = {Steinfeld, David E.}, editor = {Pacific Northwest Research Station (Portland, Or.)}, publisher = {U.S. Dept. of Agriculture, Forest Service, Pacific Northwest Research Station}, year = {1997}, pages = {7}, url = {http://soda.sou.edu/awdata/030611b1.pdf} }