RUSIELIK, R. and ZBARASZEWSKI, W. (2020) “The efficiency of scientific and tourism activity of Polish National Parks with use DEA method”, Economic and Environmental Studies, 14(3 (31), pp. 283–297. Available at: https://czasopisma.uni.opole.pl/index.php/ees/article/view/2883 (Accessed: 23 November 2024).