Angima, S., Terry, T., Dobkowski, A., Campbell, S., Grizzel, J., Harrison, R., Heninger, R., Maguire, D., Miller, R., Page-Dumroese, D., Scott, W., Zabowski, D., & State University. Extension Service, O. (2011). Best management practices for maintaining soil productivity in the Douglas-fir region. : Corvallis, Or. : Extension Service, Oregon State University.