https://theconversation.com/cumbre-de-granada-los-vetos-de-hungria-y-una-declaracion-cargada-de-geopolitica-215244
http://www.dw.com/en/turkey-eu-relations-which-countries-are-for-or-against-turkish-accession/a-40381533
https://ukandeu.ac.uk/study-of-federalism-uk-eu-relationship/?mc_cid=ef569320c7&mc_eid=815b1928ec