What is the format for the catalogue number GAD 2014 CD on July 6, 1998?
CREATE TABLE "release_history" (
  "country" text,
  "date" text,
  "label" text,
  "format" text,
  "catalogue_num" text
);
SELECT "format" FROM "release_history" WHERE "catalogue_num"='gad 2014 cd' AND "date"='july 6, 1998';