Flora of the Pacific Northwest, Hitchcock and Cronquist, Univ. of Washington Press, 7th printing, 1973.
Seed Germination Theory and Practice, Second Edition, Deno, Norman, published 1993.
Glacier Park Native Plant Nursery Propagation Records, unpublished.
Seeds: Ecology, Biogeography and Evolution of Dormancy and Germination, Baskin and Baskin, Academic Press, 1998.
Seeds of the Woody Plants of the U.S., Agriculture Handbook #450, U.S.F.S., Washington D.C., 1974.