https://www.openmarketsinstitute.org/publications/how-to-fix-supply-chains-break-the-chain
https://insightcrime.org/investigations/synthetic-silk-road-tracing-china-grey-market-precursor-chemical-trade/
https://home.kpmg.com/content/dam/kpmg/nl/pdf/2018/sector/overheid/impact-van-non-tarifaire-handelsbelemmeringen-als-gevolg-van-brexit.pdf
https://www.cer.eu/sites/default/files/insight_SL_5.11.19_2.pdf