@article{Thatcher1998,
author = {Thatcher, A.R. and Kannisto, V. and Vaupel, J.W. and Vaupel, J.W. and Romo, V.C.},
title= {The force of mortality at ages 80 to 120. Odense Monographs on Population Aging 5},
year = {1998},
doi = {10.1353/dem.2003.0018},
volume = {40},
number = {2},
pages = {201--216},
}