Bret W. Tobalske, Raymond C. Shearer, Richard L. Hutto,
Bird populations in logged and unlogged western larch/douglas-fir forest in northwestern Montana Res. Pap. INT-GTR-442. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station. 12 p.. ,vol. 442, pp. 1- ,(1991) ,
10.2737/INT-RP-442