Flora of the Pacific Northwest, Hitchcock and Cronquist, University of Washington Press,7th printing, 1981.
Seeds: Ecology, Biogeography, and Evolution of Dormancy and Germination, Baskin and Baskin, Academic Press,1998.
Aspects of the Seed Ecology of Woody Plants of the Alaskan Taiga and Tundra, Densmore, PhD. Thesis, Department of Botany, Duke University, 1979.
Glacier National Park Propagation Records,unpublished.
Propagation of Pacific Northwest Native Plants, Rose, R., Chachulski, C., and Hasse, D., Oregon State University Press, 1998.