M. Grzybowska-Brzezińska, K. B. Doczyk, and K. E. Kuśmierz, “Impact of Additional Income from the ‘Family 500+’ Program on Household Expenditures”, SOEP, vol. 6, no. 12, pp. 73–85, Dec. 2018, doi: 10.18559/SOEP.2018.12.5.