CREATE TABLE table_13670 ("Title" CLOB, "Director" CLOB, "Writer" CLOB, "Original airdate" CLOB, "Prod. Code" CLOB)

Who wrote 'The Six Stages of Marshall'?
SELECT "Writer" FROM table_13670 WHERE "Title" = 'the six stages of marshall'
SELECT "Writer" FROM "table_13670" WHERE "Title" = 'the six stages of marshall'