@article{Yashin2001,
author = {Yashin, A.I. and Ukraintsev, S.V. and Anisimov, V.N.},
title= {Have the oldest old adults ever been frail in the past? A hypothesis that explains modern trends in survival},
year = {2001},
doi = {10.1093/gerona/56.10.B432},
journal = {Journal of Gerontology: Biological Sciences},
volume = {56A},
number = {10},
pages = {B432--B442},
}