@book{1970,
	author = {Collett, D.,},
	title = {Modelling survival data in medical research /},
	publisher = {Chapman & Hall,},
	year = {1994.},
	address = {London ;},
	edition = {1st ed.},
	url = {http://www.loc.gov/catdir/enhancements/fy0744/94147528-d.html}
}