Defant, M. J.;Jackson, T. E.;Drummond, M. S.;de Boer, J. Z.;Bellon, H.;Feigenson, M. D.;Maury, R. C.;Stewart, R.H.(1992).„The geochemistry of young volcanism throughout western Panama and southeastern Costa Rica: An overview”.Journal of the Geological Society149(4): 569–579.DOI:10.1144/gsjgs.149.4.0569.