@inbook{1000027791, author={Raymond S. Greenberg and Stephen R. Daniels and W. Dana Flanders and John William Eley and John R. Boring III}, title={}, booktitle={Medical Epidemiology, 4e}, publisher={The McGraw-Hill Companies}, address={New York, NY}, year={2005}, url={accesspharmacy.mhmedical.com/content.aspx?aid=1000027791} }