@book{159735,
	author = {United States},
	title = {Soil survey manual},
	publisher = {U.S. Dept. of Agriculture},
	year = {[1993]},
	series = {United States Department of Agriculture handbook},
	address = {[Washington, D.C.]},
	note = {"This is a revision and enlargement of U.S. Department of Agriculture Handbook No. 18, the Soil survey manual, issued October 1962, and supersedes it."}
}