CREATE TABLE table_47445 ("Series Sorted" TEXT, "Title" TEXT, "Doctor" TEXT, "Featuring" TEXT, "Released" TEXT)

what is the series sorted when the released is may 2012?
SELECT "Series Sorted" FROM table_47445 WHERE "Released" = 'may 2012'
SELECT "Series Sorted" FROM "table_47445" WHERE "Released" = 'may 2012'