https://www.bruegel.org/sites/default/files/2023-09/PB%2018%202023_1.pdf
https://wwfeu.awsassets.panda.org/downloads/ets_revenues_report_2022___web___final.pdf
https://futuros.gob.es/sites/default/files/2023-09/RESILIENTEU2030.pdf
https://muse.jhu.edu/pub/423/article/930314/pdf