Betancourt Serna, Fernando2015-05-282015-05-2819830304-4319http://hdl.handle.net/11441/25073application/pdfspaAttribution-NonCommercial-NoDerivatives 4.0 Internacionalhttp://creativecommons.org/licenses/by-nc-nd/4.0/info:eu-repo/semantics/articleinfo:eu-repo/semantics/openAccess