SZEWCZYK, Helena. Sources of financing of the activity of trade unions. Z Problematyki Prawa Pracy i Polityki Socjalnej, [S. l.], v. 22, n. 5, p. 1–25, 2023. DOI: 10.31261/zpppips.2024.22.01. Disponível em: https://trrest.vot.pl/ojsus/index.php/ZPPPIPS/article/view/15121. Acesso em: 6 may. 2025.