https://www.elibrary.imf.org/downloadpdf/book/9798400224119/CH004.xml
https://ustr.gov/sites/default/files/2023-03/2023%20NTE%20Report.pdf
https://ecipe.org/wp-content/uploads/2021/09/ECI_21_PolicyBrief_12_2021_LY02.pdf
http://trade.ec.europa.eu/doclib/docs/2018/october/tradoc_157468.pdf