@book{60621,
	author = {Association of Official Analytical Chemists and Horwitz, William},
	title = {Official methods of analysis},
	publisher = {AOAC.,},
	year = {1975},
	address = {Washington, D.C. :},
	edition = {12 ed.},
	note = {---- Sup. 1-4 Washington, AOAC. 1974-77}
}