@article{ref1,
title="Bicycle safety helmets [Comment on A case-control study of the effectiveness of bicycle safety helmets. Thompson RS, Rivara FP, Thompson DC.]",
journal="New England journal of medicine",
year="1989",
author="Thompson, D. C. and Rivara, Frederick P. and Thompson, R. S.",
volume="320",
number="21",
pages="1361-1367",
abstract="unavailable]",
language="en",
issn="0028-4793",
doi="10.1056/NEJM198910263211713",
url="http://dx.doi.org/10.1056/NEJM198910263211713"
}