@article{Olshansky1987,
author = {Olshansky, S. J. and Ault, B.},
title= {The fourth stage of the epidemiologic transition: The age of delayed degenerative diseases},
year = {1987},
doi = {10.1126/science.2237414},
journal = {The Milbank Quarterly },
volume = {64},
pages = {634--639},
}