Wronowska, G., and J. Rosiek. “SOCIAL CONVERGENCE IN THE EU-28 COUNTRIES IN THE LIGHT OF THE IMPLEMENTATION OF THE EUROPE 2020 STRATEGY. THE DEA APPROACH”. Acta Scientiarum Polonorum. Oeconomia, Vol. 18, no. 3, Sept. 2019, pp. 111-9, doi:10.22630/ASPE.2019.18.3.38.