https://wiiw.ac.at/alternatives-in-the-design-of-sovereign-green-bonds-dlp-6412.pdf
https://www.eca.europa.eu/Lists/News/NEWS1801_16/INSR_SSM2_EN.pdf
https://www.project-syndicate.org/commentary/global-economy-downside-risks-by-nouriel-roubini-2017-06
https://www.boeckler.de/pdf/p_imk_study_55_2017.pdf