TRZCIELIŃSKA-POLUS, A. The regional level of paradiplomacy (on the example of Opole Voivodeship). Border and Regional Studies, [S. l.], v. 3, n. 2, p. 117–133, 2015. DOI: 10.25167/ppbs485. Disponível em: https://czasopisma.uni.opole.pl/index.php/p/article/view/485. Acesso em: 23 aug. 2025.