KACZYŃSKA , Aneta. Sources of Revenue for the European Union Budget - Current State, Weaknesses and Proposed Solutions. Studia Oeconomica Posnaniensia, Poznan, Polska, v. 2, n. 6, p. 58–76, 2014. DOI: 10.18559/tfgf2x79. Disponível em: https://journals.ue.poznan.pl/soep/article/view/3290. Acesso em: 3 sep. 2026.