What is the Label for the Covered Song named " sign o' the times " by prince .?
CREATE TABLE "cover_version" (
  "album" text,
  "release_date" text,
  "label" text,
  "format" text,
  "covered_song" text,
  "original_song" text
);
SELECT "label" FROM "cover_version" WHERE "covered_song"='\" sign o'' the times \" by prince .';