TY - GEN L1 - http://www.dbc.wroc.pl/Content/40899/PDF/PPoMP_2018_54_2_363_376.pdf L2 - http://www.dbc.wroc.pl/Content/40899 CY - Wroclaw UR - http://www.dbc.wroc.pl/dlibra/publication/edition/40899 ER -