https://ukandeu.ac.uk/our-economic-challenges-are-structural-borrowing-alone-wont-solve-them/?mc_cid=884875e416&mc_eid=815b1928ec
https://www.economiesuisse.ch/de/artikel/die-praemien-sind-zu-35-prozent-einkommensabhaengig
http://ec.europa.eu/transport/sites/transport/files/eu_air_carriers_by_country_holding_an_active_operating_licence.pdf