BULUT, Hasan; ÖNER, Yüksel; SÖZEN, Çağlar. Clustering of Member and Candidate Countries of the European Union. International Journal of Sciences: Basic and Applied Research (IJSBAR), Jordan, v. 36, n. 7, p. 18–25, 2017. Disponível em: https://www.gssrr.org/JournalOfBasicAndApplied/article/view/8274. Acesso em: 7 nov. 2025.