@booklet {Wu1989nitrates,
	title = {Recent trends in the chemistry of precipitation in the United States: Part 3. Concentrations of nitrates},
	year = {1989},
	publisher = {Department of Statistics, University of British Columbia},
	type = {131},
	address = {Vancouver, BC},
	author = {Wu, Shiying and Zidek, J.V.}
}
