@inbook{Murphy1993,
author = {Murphy, M. and Berrington, A.},
title= {Constructing period parity progression ratios from household survey data},
year = {1993},
editor = {Ní Bhrolcháin, M.},
booktitle = {New Perspectives on Fertility in Britain},
address = {London},
publisher = {HMSO},
pages = {17--32},
}