@article{Vaupel2010,
author = {Vaupel, J. W. and Zhang, Z.},
title= {Attrition in Heterogeneous Cohorts},
year = {2010},
doi = {10.4054/DemRes.2010.23.26},
journal = {Demographic Research},
volume = {23},
number = {26},
pages = {737--748},
}