CREATE TABLE table_51681 ("Race" TEXT, "Date" TEXT, "Location" TEXT, "Pole Position" TEXT, "Fastest Lap" TEXT, "Race Winner" TEXT, "Constructor" TEXT, "Report" TEXT)

Tell me the constructor for zolder
SELECT "Constructor" FROM table_51681 WHERE "Location" = 'zolder'
SELECT "Constructor" FROM "table_51681" WHERE "Location" = 'zolder'