CREATE TABLE table_37236 ("Round" FLOAT, "Date" TEXT, "Grand Prix" TEXT, "Circuit" TEXT, "125cc winner" TEXT, "250cc winner" TEXT, "MotoGP winner" TEXT, "Report" TEXT)

Which 250cc winner has a 125cc winner of bradley smith, and a MotoGP winner of casey stoner?
SELECT "250cc winner" FROM table_37236 WHERE "125cc winner" = 'bradley smith' AND "MotoGP winner" = 'casey stoner'
SELECT "250cc winner" FROM "table_37236" WHERE "125cc winner" = 'bradley smith' AND "MotoGP winner" = 'casey stoner'