Niewiadomska, A., and E. Sobolewska-Poniedziałek. “EDUCATIONAL ACTIVITY AS THE GROWTH FACTOR OF PROFESSIONAL ACTIVITY OF ELDERLY PEOPLE”. Acta Scientiarum Polonorum. Oeconomia, Vol. 15, no. 3, Sept. 2016, pp. 79-90, https://js.wne.sggw.pl/index.php/aspe/article/view/4243.