Wardeńska, Marta, Agnieszka Perzyńska, Magdalena Kochanowicz, Łukasz Pabianek, Ewa Trela, and Walery Zukow. 2017. “The Impact of Spa Treatment on Quality of Life of Elderly People”. Journal of Education, Health and Sport 7 (3):341-60. https://apcz.umk.pl/JEHS/article/view/4293.