Flora of the Pacific Northwest, Hitchcock and Cronquist, 7th edition, University of Washington Press, 1973.
Seeding Rate Statistics for Native and Introduced Species, Hassell, Wendel, U.S.D.I. and U.S.D.A., April 1996.
Seeds: Ecology, Biogeography, and Evolution of Dormancy and Germination, Baskin and Baskin, Academic Press, 1998.
Seed Germination Theory and Practice, Deno, Norman, Penn. State University, 1993.
Glacier National Park Native Plant Nursery Propagation Records, unpublished.