E. Kobos, Z. Sienkiewicz, A. Leńczuk-Gruba, and J. Parkitna, “Seniors in Warsaw and their free time in the context of planning health education”, Pol J Public Health, vol. 120, no. 2, pp. 171–176, May 2010, Accessed: Jun. 18, 2025. [Online]. Available: https://czasopisma.umlub.pl/pjph/article/view/2137