https://www.destatis.de/Europa/EN/Topic/Economy-Finance/Debt.html
https://www.socialeurope.eu/the-discreet-but-dubious-charm-of-tax-treaties
https://www.sciencedirect.com/science/article/pii/S0022199617301411
https://www.assemblee-nationale.fr/dyn/16/rapports/cion_fin/l16b1678_rapport-information#