@article{ref1,
title="Actual pedestrian visibility and the pedestrian's estimate of his own visibility",
journal="American journal of optometry and archives of American Academy of Optometry",
year="1970",
author="Allen, Merrill J. and Hazlett, R. D. and Tacker, H. L. and Graham, B. V.",
volume="47",
number="1",
pages="44-49",
abstract="<p>[Abstract unavailable]</p> <p>Language: en</p>",
language="en",
issn="0002-9408",
doi="",
url="http://dx.doi.org/"
}