@article{ref1,
title="ABC of sleep disorders. Impact and epidemiology of sleep disorders",
journal="British medical journal: BMJ",
year="1993",
author="Shapiro, C. M. and Dement, W. C.",
volume="306",
number="6892",
pages="1604-1607",
abstract="<p>[Abstract unavailable]</p> <p>Language: en</p>",
language="en",
issn="0959-8138",
doi="",
url="http://dx.doi.org/"
}