@article{Li2009,
author = {Li, T.  and Anderson, J.J.},
title= {The vitality model: A way to understand population survival and demographic heterogeneity},
year = {2009},
doi = {10.1016/j.tpb.2009.05.004},
journal = {Theoretical Population Biology},
volume = {76},
number = {2},
pages = {118--131},
}