CREATE TABLE table_name_68 (entrant VARCHAR2, engine VARCHAR2, chassis VARCHAR2)

What team uses a Cosworth DFV V8 engine and DN9 Chassis?
SELECT entrant FROM table_name_68 WHERE engine = "cosworth dfv v8" AND chassis = "dn9"
SELECT "entrant" FROM "table_name_68" WHERE "chassis" = "dn9" AND "cosworth dfv v8" = "engine"