Landi F., Russo A., Cesari M., Barillaro C., Onder G., Zamboni V., De Santis A., Pahor M., Ferrucci L., Bernabei R..  2005.  The ilSIRENTE study: A prospective cohort study on persons aged 80 years and older living in a mountain community of Central Italy. Aging - Clinical and Experimental Research. 17(6):486-493.