TY - GEN L1 - http://www.dbc.wroc.pl/Content/40887/PDF/PPoMP_2018_54_2_238_248.pdf L2 - http://www.dbc.wroc.pl/Content/40887 CY - Wroclaw UR - http://www.dbc.wroc.pl/dlibra/publication/edition/40887 ER -