http://norden.diva-portal.org/smash/get/diva2:1095959/FULLTEXT02.pdf
https://www.bruegel.org/sites/default/files/2022-11/PC%2020%202022_4.pdf
https://data.oecd.org/natincome/net-lending-borrowing-by-sector.htm
http://www.sgi-network.org/2017/About