Root diseases in Oregon and Washington conifers - Hadfield, James S.; United States. Forest Service. Pacific Northwest Region. (Portland, Or, USDA Forest Service, Pacific Northwest Region Forest Pest Management, 1986, 1986)
https://www.biodiversitylibrary.org/bibliography/178230
Keywords: Conifers|Diseases and pests|Oregon|Root rots|Roots (Botany)|Washington (State)