@book{820,
	author = {Hanke, John E., and Reitsch, Arthur G.,},
	title = {Understanding business statistics /},
	publisher = {Irwin,},
	year = {�1991.},
	series = {The Irwin series in quantitative analysis for business},
	address = {Homewood, IL :},
	url = {http://www.gbv.de/dms/hbz/toc/ht004353198.PDF}
}