https://www.tandfonline.com/doi/full/10.1080/13698249.2022.2015195?src=
https://www.documentcloud.org/documents/21416178-note-confidentiel-defense-du-12-mai-2016-ciemgg-russie
http://carnegieeurope.eu/strategiceurope/75351
https://www.nber.org/papers/w24701.pdf