Zawilińska, Bernadetta. 2015. “The Economic Value of Protected Areas - An Outline of the Issues and Research Methodology”. Krakow Review of Economics and Management Zeszyty Naukowe Uniwersytetu Ekonomicznego W Krakowie, no. 12(936) (December): 113-29. https://doi.org/10.15678/ZNUEK.2014.0936.1208.