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S., and Mac’as, J. L., 2000, Chemical characteristics of the
crater lakes of Popocatetetl, El Chichon, and Nevado de Toluca volcanoes,
Mexico, J. Volcanol. Geotherm. Res., v. 97, p. 105-125.
please note that URL of following documents may change. VN doesn't assume responsibility of their up - to date status
http://www.conabio.gob.mx/conocimiento/regionalizacion/doctos/rtp_109.pdf
http://www.conabio.gob.mx/conocimiento/regionalizacion/doctos/rhp_066.html
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