Hansen EM, Roth LF, Hamm PB, Julis. AJ. Survival, spread, and pathogenicity of Phytophthora spp. on Douglas-fir seedlings planted on forest sites. Phytopathology 70: [Internet]. 1980  ;70:422-425. Available from: http://www.apsnet.org/publications/phytopathology/backissues/Documents/1980Abstracts/Phyto70_422.htm