https://www.brookings.edu/articles/disquiet-in-the-worlds-middle-class/
https://www.imk-boeckler.de/fpdf/HBS-008792/p_imk_study_91_2024.pdf
https://orsted.com/-/media/WWW/Docs/Corp/COM/Barometer-campaign/Green-Energy-Barometer-2017_with-appendix.ashx?la=en&hash=65C5D0F30494C277249CA7622AF0229AD5B6D3CB
https://www.economiesuisse.ch/sites/default/files/publications/swisscode_e_web.pdf