http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Some observations on campground trampling & ground cover response
Some observations on campground trampling and ground cover response
Northeastern Forest Experiment Station (Radnor, Pa.)
Includes bibliographical references (page 11).
U.S. Forest Service research paper NE ; 68