Baruk, Agnieszka, and Anna Goliszek. 2019. “A VALUABLE NATURAL AREA AS A SYSTEM MARKETING PRODUCT VERSUS EXPECTATIONS OF TOURISTS AS ACTIVE PURCHASERS”. Acta Scientiarum Polonorum. Oeconomia 18 (1), 5-12. https://doi.org/10.22630/ASPE.2019.18.1.1.