
https://ukandeu.ac.uk/the-uk-internal-market-bill-breaking-law-and-reputation/?mc_cid=7627d659c2&mc_eid=815b1928ec

http://www.cesifo-group.de/ifoHome/publications/working-papers/CESifoWP/CESifoWPdetails?wp_num=6430&CESifoWP.search=+

https://www.cer.eu/sites/default/files/insight_SL_5.11.19_2.pdf