@article{Land1994,
author = {Land, K.C. and Guralnik, J.M. and Blazer, D.G.},
title= {Estimating increment-decrement life tables with multiple covariates from panel data: The case of active life expectancy},
year = {1994},
doi = {10.2307/2061887},
journal = {Demography},
volume = {31},
number = {2},
pages = {297--319},
}