PANASIUK , Aleksander. Directions for a Change in Tour Operators Market Regulation (in Poland and the European Union). Studia Oeconomica Posnaniensia, Poznan, Polska, v. 6, n. 10, p. 21–36, 2018. DOI: 10.18559/SOEP.2018.10.2. Disponível em: https://journals.ue.poznan.pl/soep/article/view/3868. Acesso em: 3 sep. 2026.