https://ec.europa.eu/commission/sites/beta-political/files/customs_controls_0.pdf
https://institute.global/insight/middle-east/assessing-israels-trade-its-arab-neighbours?utm_source=Institute+Interest&utm_campaign=591ede149a-EMAIL_CAMPAIGN_2018_03_28_COPY_01&utm_medium=email&utm_term=0_a778d447d9-591ede149a-65414641
https://www.iod.com/Portals/0/PDFs/Campaigns%20and%20Reports/Europe%20and%20trade/Going-global.pdf?ver=2018-04-04-164140-840
http://sro.sussex.ac.uk/id/eprint/110932/1/BP-70.pdf