https://library.fes.de/pdf-files/bueros/wien/19536-20220926.pdf
https://boe.es/boe/dias/2019/11/05/pdfs/BOE-A-2019-15790.pdf#BOEn
https://www.brookings.edu/articles/are-convention-delegates-bound-to-their-presidential-candidate/
https://www.socialeurope.eu/wp-content/uploads/2019/01/03_Brexit_Kroeger.pdf