@article{Kravdal1991,
author = {Kravdal, Ø and Glattre, E. and Haldorsen, T.},
title= {Positive correlation between parity and incidence of thyroid cancer: New evidence based on complete Norwegian birth cohorts},
year = {1991},
doi = {10.1002/ijc.2910490606},
volume = {49},
number = {6},
pages = {831--836},
}