@article{ref1,
title="Cigarette smoking and drug use in schoolchildren. II. Factors associated with smoking",
journal="International journal of epidemiology",
year="1981",
author="O'Connell, D. L. and Alexander, H. M. and Dobson, A. J. and Lloyd, D. M. and Hardes, G. R. and Springthorpe, H. J. and Leeder, S. R.",
volume="10",
number="3",
pages="223-231",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0300-5771",
doi="",
url="http://dx.doi.org/"
}