https://www.socialeurope.eu/2017/07/real-measure-inequality/
https://www.ips-journal.eu/topics/democracy-and-society/german-companies-have-to-ensure-decent-working-conditions-5013/
https://www.boeckler.de/pdf/p_study_hbs_376.pdf
http://The European Social Pillar – Towards An EU Minimum Wage Policy?