@book{19907,
	author = {Clearfield, Harris R. and Borowsky, Larry M.},
	title = {Case studies in gastroenterology for the house officer /},
	publisher = {Williams & Wilkins,},
	year = {c1989.},
	address = {Baltimore :},
	url = {http://www.archive.org/details/casestudiesingas00clea}
}