@book{Thatcher1998,
author = {Thatcher, A.R. and Kannisto, V. and Vaupel, J.W.},
title= {The Force of Mortality at Ages 80 and 120},
year = {1998},
address = {Denmark},
publisher = {Odense University Press.},
series = {Odense Monographs on Population Aging 5},
}