@inbook{Gérard2006,
author = {Gérard, H.},
title= {Theory building in demography},
year = {2006},
editor = {Caselli, G.},
editor = {Vallin, J.},
editor = {Wunsch, G.},
booktitle = {Demography. Analysis and Synthesis},
address = {San Diego},
publisher = {Academic Press},
pages = {647--660},
}