https://www.imf.org/external/pubs/ft/fandd/2021/12/pdf/Kimball.pdf
https://www.socialeurope.eu/the-circular-economy-a-geometry-lesson
https://www.economiesuisse.ch/de/artikel/hohe-loehne-tiefe-ungleichheit-und-ein-attraktiver-standort
https://www.corriere.it/politica/22_novembre_18/di-maio-nuova-vita-sara-inviato-speciale-ue-golfo-persico-trattare-prezzo-petrolio-gas-0805b148-6720-11ed-b05a-06c1012dfe21.shtml