TY - JOUR AU - Kučera, Radan TI - A generalization of a unit index of Greither JO - Communications in Mathematics PY - 1998 SP - 149 EP - 154 VL - 06 IS - 1 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/COMIM_1998__6_1_a17/ LA - en ID - COMIM_1998__6_1_a17 ER -