https://www.eia.gov/energyexplained/us-energy-facts/imports-and-exports.php
http://www.theglobalipcenter.com/wp-content/uploads/2018/02/GIPC_IP_Index_2018.pdf
https://www.somo.nl/wp-content/uploads/2021/06/ViacomCBS.pdf
https://static.europeanchamber.com.cn/upload/documents/documents/Executive_Position_Paper_2019_2020%5B757%5D.pdf