
https://theconversation.com/idea-of-eu-citizenship-still-intangible-for-most-europeans-230994

http://www.elperiodico.com/es/politica/20171226/que-es-tabarnia-propuesta-secesion-barcelona-tarragona-resto-cataluna-6517873

http://cer.eu/sites/default/files/report_relaunching_eu_nov17.pdf