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Hanna Kruk
Gdynia Maritime University, Faculty of Entrepreneurship and Quality Science, Department of Economics and Management, Morska 81–87, 81-225 Gdynia, Poland, phone: +48 58 6901544
Bożena Kornatowska
Institute of Environmental Protection-NRI, Department of Nature and Landscape Conservation, Kolektorska 4, 01-692 Warsaw, Poland