TY - JOUR AU - Assia P. Rousseva TI - A Necessary Condition for the Existence of Arcs and Codes JO - Mathematica balkanica PY - 2004 SP - 177 VL - 18 IS - 1-2 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/MABA_2004_18_1-2_a18/ ID - MABA_2004_18_1-2_a18 ER -