@article{ref1,
title="Acoustical study of a rapid transit system",
journal="American Industrial Hygiene Association journal",
year="1974",
author="Chang, H. C. and Hermann, E. R.",
volume="35",
number="10",
pages="640-653",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0002-8894",
doi="10.1080/0002889748507084",
url="http://dx.doi.org/10.1080/0002889748507084"
}