CREATE TABLE table_name_40 (aircraft_flown VARCHAR2, axis_unit VARCHAR2, enemy_aircraft VARCHAR2)

What was the aircraft flown when the axis unit was luftwaffe (**) and the enemy aircraft was ju.88?
SELECT aircraft_flown FROM table_name_40 WHERE axis_unit = "luftwaffe (**)" AND enemy_aircraft = "ju.88"
SELECT "aircraft_flown" FROM "table_name_40" WHERE "axis_unit" = "luftwaffe (**)" AND "enemy_aircraft" = "ju.88"