@article{Ni Bhrolchain1987,
author = {Ni Bhrolchain, M.},
title= {Period parity progression ratios and birth intervals in England and Wales, 1941–1971: A synthetic life table analysis},
year = {1987},
doi = {10.1080/0032472031000142556},
volume = {41},
number = {1},
pages = {103--125},
}