Includes bibliographical references (pages 24-27).
Also available via Internet from the U.S. Forest Service web site. Address as of 04/09/08: http://www.fs.fed.us/pnw/pubs/pnw%5Fgtr608.pdf; current access is available via PURL.
Microfiche. [Washington, D.C.] : Supt. of Docs., U.S. G.P.O., 2004. 1 microfiche : negative.