TY - GEN L1 - http://www.dbc.wroc.pl/Content/40901/PDF/PPoMP_2018_54_2_386_394.pdf L2 - http://www.dbc.wroc.pl/Content/40901 CY - Wroclaw UR - http://www.dbc.wroc.pl/dlibra/publication/edition/40901 ER -