Mroczek-Czetwertyńska, Agnieszka, and Sławomir Czetwertyński. “Impact of Regulations on Transparency of Spa & Wellness Market in Poland”. Oeconomia Copernicana 4, no. 4 (December 31, 2013): 91–102. Accessed January 21, 2026. https://oeconomia.pl/index.php/oc/article/view/426.