@article{Lotka1922,
author = {Lotka, A.J.},
title= {The stability of the normal age distribution},
year = {1922},
doi = {10.1073/pnas.8.11.339},
URL = {http://dx.doi.org/10.1073/pnas.8.11.339},
volume = {8},
number = {11},
pages = {339--345},
}