@article{ref1,
title="The efficiency and walking speed of visually impaired people",
journal="Ergonomics",
year="1986",
author="Clark-Carter, D. D. and Heyes, A. D. and Howarth, C. I.",
volume="29",
number="6",
pages="779-789",
abstract="<p>[Abstract unavailable]</p> <p>Language: en</p>",
language="en",
issn="0014-0139",
doi="",
url="http://dx.doi.org/"
}