@book{136164,
	author = {Whitehead, D. C. and ebrary, Inc.},
	title = {Nutrient elements in grassland},
	publisher = {CABI Pub.,},
	year = {2000.},
	address = {New York :},
	url = {http://site.ebrary.com/lib/rucke/Doc?id=10170095}
}