https://www.osce.org/library/14127?download=true
https://www.geostrategy.org.uk/britains-world/unseen-but-vital-britain-and-undersea-security/?utm_source=newsletter&utm_medium=email&utm_campaign=09%2F03%2F2023
https://www.socialeurope.eu/smersh-putin-reinstates-stalins-anti-spy-unit
https://www.ips-journal.eu/topics/foreign-and-security-policy/a-message-of-disunity-7363/