https://www.nuffieldtrust.org.uk/news-item/privatisation-by-the-front-door-what-does-a-new-public-private-gp-model-mean
https://www.wto.org/english/tratop_e/envir_e/trade-climate-change_info_brief_no7_e.pdf
https://www.oecd-ilibrary.org/docserver/cb6d9eca-en.pdf?expires=1654579866&id=id&accname=guest&checksum=058AA472061C4F1B77F0DDF5D1BCBA31