Who was the partner for the game on October 20, 2013?
CREATE TABLE "doubles_11_5_titles_6_runners_up" (
  "outcome" text,
  "date" text,
  "surface" text,
  "partner" text,
  "opponents" text,
  "score" text
);
SELECT "partner" FROM "doubles_11_5_titles_6_runners_up" WHERE "date"='october 20, 2013';