
http://www.guengl.eu/uploads/news-documents/Working_paper_Border_controls_on_cross_border_trade_in_goods.pdf

https://ecipe.org/wp-content/uploads/2024/07/ECI_24_PolicyBrief_15-2024_LY04.pdf

https://unctad.org/system/files/official-document/wir2021_overview_en.pdf