1. Reuben DB, Herr KA, Pacala JT, Pollock BG, Potter JF, Semla TP. Geriatrics at Your Fingertips. 8th ed. New York: American Geriatrics Society; 2006.
2. DeFrances CJ, Podgornik MN. 2004 National Discharge Survey. 371. 5-4-2006. Hyattsville, MD: National Center for Health Statistics. Advance Data from Vital and Health Statistics.
3. Mangano DT. Preoperative risk assessment: many studies, few solutions. Is a cardiac risk assessment paradigm possible? Anesthesiology 1995;83:897–901.
4. Ochsner A. Is risk of operation too great in the elderly? Geriatrics 1927;22:121.
5. Klopfenstein CE, Herrmann FR, Michel JP, Clergue F, Forster A. The influence of an aging surgical population on the anesthesia workload: a ten-year survey. Anesth Analg 1998;86:1165–1170.