Who were the opponents in the match or matches that ended in a score of W/O?
CREATE TABLE "doubles_8_4" (
  "outcome" text,
  "date" text,
  "surface" text,
  "partner" text,
  "opponents_in_final" text,
  "score_in_final" text
);
SELECT "opponents_in_final" FROM "doubles_8_4" WHERE "score_in_final"='w/o';