@article{ref1,
title="Two types of tractor four-wheel drive engage alarm for use on slopes",
journal="Journal of agricultural engineering research",
year="1986",
author="Owen, G. M.",
volume="33",
number="2",
pages="155-158",
abstract="The number of four-wheel drive tractors in use on and off farms continues to increase. On steep sloping land, the four-wheel drive tractor is much safer to operate than the equivalent two-wheel drive. Thus, failure to engage four-wheel drive when needed is becoming an increasing hazard, causing many serious tractor accidents. This technical note describes two techniques for alerting the driver of this hazard should he forget.<p /><p>Language: en</p>",
language="en",
issn="0021-8634",
doi="10.1016/S0021-8634(86)80037-3",
url="http://dx.doi.org/10.1016/S0021-8634(86)80037-3"
}