@article{Belmont1973,
author = {Belmont, L. and Marolla, F.A.},
title= {Birth order, family size, and intelligence},
year = {1973},
doi = {10.1126/science.182.4117.1096},
journal = {Science},
volume = {182},
number = {4117},
pages = {1096--1101},
}