CREATE TABLE table_59631 ("Round" TEXT, "Date" TEXT, "Event" TEXT, "Circuit" TEXT, "Winning Driver" TEXT, "Winning Team" TEXT)

Who was the winning team for circuit zolder?
SELECT "Winning Team" FROM table_59631 WHERE "Circuit" = 'circuit zolder'
SELECT "Winning Team" FROM "table_59631" WHERE "Circuit" = 'circuit zolder'