@inbook{545000, author={Raymond S. Greenberg and Stephen R. Daniels and W. Dana Flanders and John William Eley and John R. Boring III}, title={Chapter 1. Introduction to Epidemiology}, booktitle={Medical Epidemiology, 4e}, publisher={The McGraw-Hill Companies}, address={New York, NY}, year={2005}, url={accessmedicine.mhmedical.com/content.aspx?aid=545000} }