@article{ref1,
title="On difficulties in localizing ambulance sirens",
journal="Human factors",
year="1980",
author="Porter, D. and Caelli, T.",
volume="22",
number="6",
pages="719-724",
abstract="Abstract unavailable.",
language="",
issn="0018-7208",
doi="",
url="http://dx.doi.org/"
}