@article{ref1,
title="Depression, a public health problem",
journal="Salud publica de Mexico",
year="1981",
author="Calderón Narváez, G.",
volume="23",
number="5",
pages="503-508",
abstract="<p>[Abstract unavailable]</p><p>Language: es</p>",
language="es",
issn="0036-3634",
doi="",
url="http://dx.doi.org/"
}