@inbook{Caselli2005,
author = {Caselli, G. and Vallin, J.},
title= {Frequency surfaces and isofrequency lines},
year = {2005},
editor = {Caselli, G.},
editor = {Vallin, J.},
editor = {Wunsch, G.},
booktitle = {Demography: Analysis and synthesis},
address = {San Diego},
publisher = {Academic Press},
pages = {69‒78},
}