@inbook{Gavrilov2003,
author = {Gavrilov, L.A. and Heuveline, P.},
title= {Aging of Population},
year = {2003},
editor = {Demeny, P.},
editor = {McNicoll, G.},
booktitle = {The Encyclopedia of Population},
address = {New York},
publisher = {Macmillan Reference USA},
pages = {32--37},
}