MLA

Bousfield, Wayne E, Hubert E Meyer, and United States. Forest Service. Northern Region. State & Private Forestry. Potential for Defoliation of Ponderosa Pine Stands by Pine Butterfly On the Bitterroot and Lolo National Forests, Montana In 1972. : Missoula, Mont. : USDA Forest Service, Northern Region, Division of State and Private Forestry, 1972.