https://www.socialeurope.eu/wp-content/uploads/2019/09/Occ-Pap-14.pdf
https://www.otto-brenner-stiftung.de/fileadmin/user_data/stiftung/Aktuelles/AH93/AH_93_Haller_Web.pdf
https://www.frontiersin.org/articles/10.3389/fpos.2021.678526/full
https://www.opendemocracy.net/neweconomics/magic-money-tree-dont-let-politicians-tell-otherwise/