https://infacts.org/fight-brexit-including-changing-mind/
http://www.conservativehome.com/platform/2017/05/neale-richmond-no-deal-between-britain-and-the-eu-would-be-a-disaster-for-ireland.html
https://theconversation.com/la-anomalia-empirica-de-las-elecciones-en-argentina-donde-dos-mas-dos-no-suman-cuatro-217319