@inbook{Beard1959,
author = {Beard, R.E.},
title= {Note on Some Mathematical Mortality Models},
year = {1959},
editor = {Wolstenholme, G.E.W.},
editor = {O'Connor, M.},
booktitle = {The Lifespan of Animals. Ciba Foundation Colloquium on Ageing},
address = {Boston, MA: Little, Brown and Company},
pages = {302--311},
}