https://www.politico.eu/article/spain-election-outcome-explained-pedro-sanchez-alberto-nunez-feijoo-socialist-popular-party-vox/
http://www.eba.europa.eu/documents/10180/2101654/Letter+to+MEPs+on+the+request+to+investigate+a+possible+BUL+under+Article+17+of+Regulation+%28EU%29%20No+10932010+-+24092018.pdf
https://ec.europa.eu/research/evaluations/pdf/archive/other_reports_studies_and_documents/hlg_2017_report.pdf