@misc{Alexandrowicz_Zofia_4._2000, author={Alexandrowicz, Zofia}, volume={Nr 46}, copyright={Creative Commons Attribution BY 3.0 PL license}, journal={Studia Naturae}, address={Kraków}, howpublished={online}, year={2000}, publisher={Institute of Nature Conservation of the Polish Academy of Sciences}, language={pol}, title={4. History of efforts for the Crystal Caves' protection}, type={Text}, URL={http://rcin.org.pl/iop/Content/79208/PDF/KR038_93058_r2000-t46_SN-Alexandrowicz-29-34.pdf}, keywords={Wieliczka salt mine, Crystal Caves}, }