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Glacier Park Native Plant Nursery Propagation Records, unpublished.
Seeds: Ecology, Biogeography and Evolution of Dormancy and Germination, Baskin and Baskin, Academic Press, 1998.
Propagation of Pacific Northwest Native Plants, Rose, R., Chachluski,C., and Hasse, D., Oregon State University Press, 1998.