BĄK, I.; SPOZ, A.; ZIOŁO, M. Sustainable Development Levels and Convergence Patterns in EU Countries in 2015, 2019 and 2023. Journal for Perspectives of Economic Political and Social Integration, [S. l.], v. 31, n. 2, p. 309–337, 2025. DOI: 10.18290/pepsi-2025-0025. Disponível em: https://czasopisma.tnkul.pl/index.php/jpepsi/article/view/4650. Acesso em: 11 jan. 2026.