Kujawska, Agnieszka, Radosław Perkowski, Joanna Androsiuk-Perkowska, Natalia Skierkowska, Małgorzata Gajos, Weronika Topka, Sławomir Kujawski, and Kornelia Kędziora-Kornatowska. 2017. “Physical Activity in Healthy, Older People. How Many Drops of Sweat Away from Gain the Health Benefit?”. Journal of Education, Health and Sport 7 (7):412-22. https://apcz.umk.pl/JEHS/article/view/4640.