
https://publications.parliament.uk/pa/ld201719/ldselect/ldeucom/15/15.pdf

https://www.nao.org.uk/wp-content/uploads/2018/01/Implementing-the-UKs-exit-from-the-European-Union-the-Deparment-for-International-Trade.pdf

https://www.wto.org/english/res_e/booksp_e/wtr23_e/wtr23_e.pdf