@book{23996,
	author = {Silman, Alan J. and Macfarlane, Gary J. and ebrary, Inc.},
	title = {Epidemiological studies},
	publisher = {Cambridge University Press,},
	year = {2002.},
	address = {Cambridge ;},
	edition = {2nd ed.},
	note = {Includes index.},
	url = {http://site.ebrary.com/lib/rucke/Doc?id=10019072}
}