@book{204977,
	author = {Källén, Anders.},
	title = {Understanding biostatistics /},
	publisher = {Wiley,},
	year = {2011.},
	series = {Statistics in practice},
	address = {Chichester, West Sussex, U.K. :},
	url = {http://onlinelibrary.wiley.com/book/10.1002/9781119992677}
}