USDA Forest Service. North Central Forest and Range Experiment Station, St. Paul, Minn.
Research Note NC-232
Anderson, Robert L.; Schipper, Arthur L. Jr. 1978. A system for predicting the amount of Phellinus (Fomes) igniarius rot in trembling aspen stands. Research Note NC-232. St. Paul, MN: U.S. Dept. of Agriculture, Forest Service, North Central Forest Experiment Station