
http://www.europeaninstitute.org/index.php/311-european-affairs/ea-october-2017/2242-as-chinese-investment-rises-in-europe-brussels-proposes-greater-scrutiny-of-foreign-purchases-of-eu-based-companies

https://www.ispionline.it/it/pubblicazione/rotte-nellartico-quale-futuro-per-i-commerci-sulla-via-del-nord-227020

https://www.esri.ie/system/files/publications/SUSTAT128_2.pdf