What is the i/o bus for the brand name Core i3-21xx?
CREATE TABLE "core_i3" (
  "codename_main_article" text,
  "brand_name_list" text,
  "cores" real,
  "l3_cache" text,
  "socket" text,
  "tdp" text,
  "i_o_bus" text
);
SELECT "i_o_bus" FROM "core_i3" WHERE "brand_name_list"='Core i3-21xx';