CREATE TABLE "series_1" (
  "series_sorted" text,
  "title" text,
  "doctor" text,
  "featuring" text,
  "released" text
);

Question: What was the date of release for the episode sorted value of 6Y/AA?
SQL: SELECT "released" FROM "series_1" WHERE "series_sorted"='6y/aa';

Question: What is the series sorted value for the episode released December 2009?
SQL: SELECT "series_sorted" FROM "series_1" WHERE "released"='december 2009';