@article{ref1,
title="A laboratory investigation of signal indications for protected left turns",
journal="Human factors",
year="1974",
author="King, L. E. and Plummer, R. W.",
volume="16",
number="1",
pages="37-45",
abstract="Abstract unavailable.",
language="",
issn="0018-7208",
doi="",
url="http://dx.doi.org/"
}