@article{Vaupel1979,
author = {Vaupel, J.W. and Manton, K.G. and Stallard, E.},
title= {The impact of heterogeneity in individual frailty on the dynamics of mortality},
year = {1979},
doi = {10.2307/2061224},
journal = {Demography},
volume = {16},
number = {3},
pages = {439--454},
}