@inbook{Willekens1999,
author = {Willekens, F.J.},
title= {The life course: models and analysis},
year = {1999},
editor = {Dykstra, P.A.},
editor = {Van Wissen, L.J.G.},
booktitle = {Population Issues: An Interdisciplinary Focus},
address = {New York},
publisher = {Kluwer Academic},
pages = {23--52},
}