https://www.mckinsey.com/mgi/our-research/the-complication-of-concentration-in-global-trade
https://wiiw.ac.at/austria-s-economic-relations-with-the-eu-eastern-partnership-countries-and-russia-dlp-6925.pdf
https://trade.ec.europa.eu/doclib/docs/2021/february/tradoc_159438.pdf