CREATE TABLE table_17971 ("Round" FLOAT, "Circuit" TEXT, "Date" TEXT, "Length" TEXT, "Pole Position" TEXT, "GT3 Winner" TEXT, "GTC Winner" TEXT)

what are all the circuit for 9 september and gt3 winner hector lester allan simonsen
SELECT "Circuit" FROM table_17971 WHERE "Date" = '9 September' AND "GT3 Winner" = 'Hector Lester Allan Simonsen'
SELECT "Circuit" FROM "table_17971" WHERE "Date" = '9 September' AND "GT3 Winner" = 'Hector Lester Allan Simonsen'