@article{Kyrklund-Blomberg1998,
author = {Kyrklund-Blomberg, N.B. and Cnattingius, S.},
title= {Preterm birth and maternal smoking: Risks related to gestational age and onset of delivery},
year = {1998},
doi = {10.1016/S0002-9378(98)70214-5},
volume = {179},
number = {4},
pages = {1051--1055},
}