https://infacts.org/theresa-mays-flip-flops-u-turns/
https://blogs.sussex.ac.uk/uktpo/2017/06/12/disentangling-brexit-trade-politics-and-policies/
https://ukandeu.ac.uk/wp-content/uploads/2019/12/Brexit-the-manifestos-uncovered.pdf
https://www.esri.ie/system/files/publications/SUSTAT117.pdf