@inbook{Billari2004,
author = {Billari, F.C. and Ongaro, F.},
title= {First stages in partnership history and in sexual experiences},
year = {2004},
editor = {Dalla Zuanna, G.},
editor = {Crisafulli, C. },
booktitle = {Sexual behaviour of Italian students},
address = {Messina},
publisher = {Dipartimento Statistico, Università di Messina},
pages = {107--124},
}