CREATE TABLE table_511 ("Series #" FLOAT, "Season #" FLOAT, "Title" TEXT, "Directed by" TEXT, "Written by" TEXT, "Original air date" TEXT, "Total viewers  ( in millions ) " TEXT)

Name the people who wrote number 67
SELECT "Written by" FROM table_511 WHERE "Series #" = '67'
SELECT "Written by" FROM "table_511" WHERE "Series #" = '67'