Karpio, Andrzej, and Dorota Żebrowska-Suchodolska. “POLISH OPEN-END PENSION FUNDS PERFORMANCE AND ITS PERSISTANCE”. Acta Scientiarum Polonorum. Oeconomia 15, no. 1 (March 30, 2016): 15–25. Accessed April 30, 2024. https://aspe.sggw.edu.pl/article/view/399.