Blank, Stephen. "The Critical Black Sea Zone." Connections: The Quarterly Journal 21, no. 4 (2022): 115-128.

Tsvetkov, Georgi. "Maritime Defence Investment Policy of the Republic of Bulgaria." Information & Security: An International Journal 27, no. 2 (2011): 163-173.

Petrov, Peter. "Towards Creation of a Unified Information System of the Navies of the Black Sea Countries." Information & Security: An International Journal 6 (2001): 94-101.