@article{ref1,
title="Mental load, heart rate and heart rate variability",
journal="Psychologische Forschung",
year="1970",
author="Blitz, P. S. and Hoogstraten, J. and Mulder, G.",
volume="33",
number="4",
pages="277-288",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0033-3026",
doi="",
url="http://dx.doi.org/"
}