https://www.economiesuisse.ch/de/artikel/umweltverantwortungsinitiative-immer-groessere-ziele-statt-konkrete-massnahmen
https://www.taxpolicycenter.org/sites/default/files/publication/163549/report-taxing-business-incomes-evidence-from-the-survey-of-consumer-finances.pdf
https://visegradinsight.eu/the-key-to-their-future-coding-hungary/