KOŚCIÓŁEK, Szczepan. Do sports clubs differ from other non-governmental organizations in terms of revenue sources? The case of Poland. Ekonomia i Prawo. Economics and Law. Online. 30 September 2019. Vol. 18, no. 3, pp. 283-294. [Accessed 27 November 2024]. DOI 10.12775/EiP.2019.020.