What is the date of the game where the line judge was Bob Beeks, the head linesman was Jerry Bergman, and Paul Baetz was the back judge?
CREATE TABLE "nfl_championships" (
  "game" text,
  "date" text,
  "referee" text,
  "umpire" text,
  "head_linesman" text,
  "line_judge" text,
  "field_judge" text,
  "back_judge" text
);
SELECT "date" FROM "nfl_championships" WHERE "line_judge"='bob beeks' AND "head_linesman"='jerry bergman' AND "back_judge"='paul baetz';