CREATE TABLE table_2140071_8 (coach VARCHAR, premier_date VARCHAR, episode VARCHAR)

What coach premiered February 16, 2008 later than episode 21.0?
SELECT coach FROM table_2140071_8 WHERE premier_date = "February 16, 2008" AND episode > 21.0
SELECT "coach" FROM "table_2140071_8" WHERE "February 16, 2008" = "premier_date" AND "episode" > 21.0