References and Bibliography
Books
- Identification Guide to the Trees of Canada, Jean Lauriault, Fitzhenry & Whiteside, 1989.
- The Plant Book, D.J. Mabberley, Cambridge University Press, 1987.
- The Audubon Society Field Guide to North American Trees, Alfred A. Knopf, Inc., 1980.
- Forest Trees of the United States and Canada, and How to Identify 
Them, Elbert L. Little,Jr., Dover Publications Inc.,1979.
- The Botanical World, D.K. Northington and J.R.Goodin, Times Mirror/Mosby College Publishing, 1984.
- Trees of North America and Europe,  Roger Phillips, Random House, 1978.
Hyperlinks
- Conifers in the Garden,  American Conifer Association.
- The Conifer Conservation Program,  Royal Botanic Garden Edinburgh.
- Many Botany Links,  Oberon University.
- 
       The Families of Flowering plants: Descriptions and Illustrations ,  Watson, L., and Dallwitz, M.J., Cornell University.
- The Model Forest Program  Canadian Forest Service.
- Botanic Gardens  University of Delaware.
- Urban Forestry  Michigan State University Extension Database.
- Trees  The DENE Culture - Northwest Territories, Canada.
- Oregon's Heritage Trees
- 
    The NCSU Arboretum ,  North Carolina State University.
 
