@article{Keyfitz1997,
author = {Keyfitz, B.L. and Keyfitz, N.},
title= {The McKendrick partial differential equation and its uses in epidemiology and population study},
year = {1997},
doi = {10.1016/S0895-7177(97)00165-9},
journal = {Mathematical and Computer Modelling},
volume = {26},
number = {6},
pages = {1--9},
}