ABBA, Saliou. The intelligence battle in the Gulf of Guinea: Espionage and counter-espionage operations in Spanish Guinea. Scientia Militaria - South African Journal of Military Studies, [S. l.], v. 50, n. 3, p. 89–102, 2022. DOI: 10.5787/50-3-1392. Disponível em: https://www.journals.ac.za/index.php/pub/article/view/1392. Acesso em: 11 jun. 2026.