@article{Boyd2007,
author = {Boyd, C.M. and Weiss, C.O. and Halter, J. and Han, K.C. and Ershler, W.B. and Fries, L.},
title= {Comorbidity. Framework for evaluating disease severity measures in older adults with comorbidity},
year = {2007},
journal = {Journal of Gerontology: Medical Sciences},
volume = {62A},
number = {3},
pages = {286--295},
}