CREATE TABLE table_31008 ("No. in series" FLOAT, "No. in season" FLOAT, "Title" TEXT, "Directed by" TEXT, "Written by" TEXT, "Original air date" TEXT, "U.S. viewers  ( millions ) " TEXT)

Who wrote the episode that was directed by Milan Cheylov?
SELECT "Written by" FROM table_31008 WHERE "Directed by" = 'Milan Cheylov'
SELECT "Written by" FROM "table_31008" WHERE "Directed by" = 'Milan Cheylov'