Flora of the Pacific Northwest, Hitchcock and Cronquist, Univ. of Washington Press, 7th printing, 1990.
Seed Germination Theory and Practice, Second Edition, Deno, Norman, published 1993.
Glacier Park Native Plant Nursery Propagation Records, unpublished.
The Reference Manual of Woody Plant Propagation, Dirr and Heuser, Varsity Press, Inc., 1987.
Seeds of the Woody Plants of the U.S., Agriculture Handbook #450, U.S.F.S., Washington DC.
Seeds: Ecology, Biogeography, and Evolution of Dormancy and Germination, Baskin and Baskin, Academic Press, 1998.
Propagation of Pacific Northwest Native Plants, Rose,R., Chachulski, C., and Haase, D. Oregon State University Press,1998.