@book {Grossman2007USGS,
	title = {The National Geochemical Survey {\textendash}- Database and Documentation, Version 5},
	year = {2008},
	pages = {45},
	publisher = {U.S. Geological Survey},
	organization = {U.S. Geological Survey},
	address = {Reston, VA},
	editor = {Grossman, J.N. and Grosz, A.E. and Schweitzer, P.N. and Schruben, P.G.}
}