What episode was written by Bobby Bell and Bill Lee?
CREATE TABLE "table1_12226390_4" (
  "no_in_series" real,
  "no_in_season" real,
  "title" text,
  "directed_by" text,
  "written_by" text,
  "original_air_date" text,
  "production_code" real
);
SELECT MAX("no_in_season") FROM "table1_12226390_4" WHERE "written_by"='Bobby Bell and Bill Lee';