Bieniek - Majka, Maryla. “COLLECTIVE ACTION THEORY OF MANCUR OLSON ON THE EXAMPLE OF INTEGRATED FRUIT AND VEGETABLE PRODUCERS”. Proceedings of the International Scientific Conference "Economic Sciences for Agribusiness and Rural Economy"0, no. 3 (January 15, 2020). Accessed March 2, 2021. https://js.wne.sggw.pl/index.php/esare/article/view/3341.