https://www.wto.org/english/tratop_e/tpr_e/s434_e.pdf
http://trade.ec.europa.eu/doclib/docs/2019/june/tradoc_157964.pdf
https://ukandeu.ac.uk/explainers/the-protocol-on-ireland-northern-ireland/?mc_cid=2bd4dc8e93&mc_eid=815b1928ec
https://cepr.org/voxeu/columns/eus-strategic-dependencies-unveiled