@article{Fried2004,
author = {Fried, L.P. and Ferrucci, L. and Darer, J. and Williamson, J.D. and Anderson, G.},
title= {Untangling the concepts of disability, frailty, and comorbidity: Implications for improved targeting and care},
year = {2004},
doi = {10.1093/gerona/59.3.M255},
volume = {59},
number = {3},
pages = {255--263},
}