https://stratcomcoe.org/cuploads/pfiles/Nato-Cyber-Report_11-06-2021-4f4ce.pdf
https://www.cer.eu/sites/default/files/insight_CB_US_24.10.22.pdf
https://www.brookings.edu/blog/up-front/2018/07/12/as-trump-twists-natos-arm-lets-run-the-math-on-defense-spending/?utm_campaign=Brookings%20Brief&utm_source=hs_email&utm_medium=email&utm_content=64421876
https://rusi.org/sites/default/files/the_silent_threat_web_version.pdf