@inbook{van de Walle1993,
author = {van de Walle, E.},
title= {Recent trends in marriage ages},
year = {1993},
editor = {Foote, K.A.},
editor = {Hill, K.H.},
editor = {Martin, L.G.},
booktitle = {Demographic change in sub-Saharan Africa},
address = {Washington, D.C.},
publisher = {National Academy Press},
pages = {117--152},
}