@article{Zheng2011,
author = {Zheng, H. and Yang, Y. and Land, K.C.},
title= {Heterogeneity in the Strehler-Mildvan General Theory of Mortality and Aging},
year = {2011},
doi = {10.1007/s13524-011-0013-8},
journal = {Demography},
volume = {48},
number = {1},
pages = {267--290},
}