@article{Gribble1993,
author = {Gribble, J.N.},
title= {Birth intervals, gestational age, and low birth weight: Are the relationships confounded?},
year = {1993},
doi = {10.1080/0032472031000146776},
journal = {Population Studies},
volume = {47},
number = {2},
pages = {133--146},
}