TY - GEN L1 - http://www.dbc.wroc.pl/Content/40909/PDF/PPoMP_2018_54_2_467_475.pdf L2 - http://www.dbc.wroc.pl/Content/40909 CY - Wroclaw UR - http://www.dbc.wroc.pl/dlibra/publication/edition/40909 ER -