https://www.europarl.europa.eu/resources/library/media/20201020RES89705/20201020RES89705.pdf
https://cms.ringiermedienschweiz.ch/sites/default/files/media/document/biianz09_wef_e_1.pdf
http://www.euronews.com/2017/06/09/catalonia-announces-independence-referendum?utm_source=newsletter&utm_medium=en&utm_content=catalonia-announces-independence-referendum&_ope=eyJndWlkIjoiZjU3Y2JhYmUwMGUxZDFiNTUxOTU1ZDljNzExNTI1MmEifQ==
https://www.vatican.va/content/leo-xiii/en/encyclicals/documents/hf_l-xiii_enc_15051891_rerum-novarum.html