# -*- coding: utf-8 -*-
require "rexml/document"
File.open("sample.xml") do |file|
  document = REXML::Document.new file
  puts REXML::XPath.first(document, "/document/header/anno_publicacion/text()")
  puts REXML::XPath.first(document, "/document/header/año_publicacion/text()")
  puts REXML::XPath.first(document, "/document/header/año_publicación/text()")
end