https://www.brookings.edu/articles/europes-messy-russian-gas-divorce/
https://rusi.org/commentary/russias-reach-exceeds-its-grasp-over-karabakh-conflict?utm_source=RUSI+Newsletter&utm_campaign=f8c06368b6-EMAIL_CAMPAIGN_2020_09_10_09_43_COPY_01&utm_medium=email&utm_term=0_0c9bbb5ef0-f8c06368b6-47711229
https://sipri.org/sites/default/files/2017-12/sipriinsights1712_.pdf
https://www.economiesuisse.ch/de/artikel/die-praemien-sind-zu-35-prozent-einkommensabhaengig