@article{Diehr2007a,
author = {Diehr, P. and Derleth, A. and Newman, A.B. and Cai, L. },
title= {The number of sick persons in a cohort},
year = {2007a},
doi = {10.1177/0164027507305727},
journal = {Research on Aging},
volume = {29},
number = {6},
pages = {555--575},
}