@article{ref1,
title="Activity and rest in old age",
journal="Anales de la Real Academia Nacional de Medicina",
year="1967",
author="Calvo melendro, J.",
volume="84",
number="3",
pages="307-327",
abstract="<p>[Abstract unavailable]</p><p>Language: es</p>",
language="es",
issn="0034-0634",
doi="",
url="http://dx.doi.org/"
}