list the leaders of all the cities through which the altar frontal from la seu d'urgell or of the apostles river flows ?
SELECT DISTINCT var_uri where brack_open dbr_Altar_frontal_from_La_Seu_d'Urgell_or_of_The_Apostles dbp_city var_x sep_dot var_x dbo_leaderName var_uri sep_dot var_x a dbo_City brack_close