@book{1728,
	author = {Gordis, Leon,},
	title = {Epidemiology /},
	publisher = {Elsevier/Saunders,},
	year = {c2009.},
	address = {Philadelphia :},
	edition = {4th ed.},
	url = {https://www.slideshare.net/mehreen833/download-epidemiology-4th-edition-leon-gordis-pdf}
}