@book{28598,
	author = {Kirkwood, Betty R. and Sterne, Jonathan A. C.},
	title = {Essential medical statistics /},
	publisher = {Blackwell Science,},
	year = {2003.},
	address = {Malden, Mass. :},
	edition = {2nd ed.},
	note = {Rev. ed. of: Essentials of medical statistics / Betty R. Kirkwood. 1988.}
}