@article{ref1,
title="Quartiles of proportional mortality. New indications of health with relation to the socio-economic conditions",
journal="Revista ecuatoriana de higiene y medicina tropical",
year="1969",
author="Enderica Vélez, R.",
volume="26",
number="3",
pages="199-217",
abstract="<p>[Abstract unavailable]</p><p>Language: es</p>",
language="es",
issn="0013-0745",
doi="",
url="http://dx.doi.org/"
}