Jacuch, Andrzej. “European Union Response to Hybrid Threats . 11”. In Bezpieczeństwo Regionalne: Węzłowe Problemy I Procesy, edited byPiotr Bajor, Societas, Vol. 132:11–25. Societas. Poland: Księgarnia Akademicka Publishing, 2020. Accessed September 18, 2025. https://books.akademicka.pl/publishing/catalog/book/215/chapter/3736.