CREATE TABLE table_15139 ("Name" TEXT, "Circuit" TEXT, "Date" TEXT, "Winning driver" TEXT, "Winning constructor" TEXT, "Report" TEXT)

Who was the winning driver of the Savio Circuit with the constructor Itala?
SELECT "Winning driver" FROM table_15139 WHERE "Winning constructor" = 'itala' AND "Name" = 'savio circuit'
SELECT "Winning driver" FROM "table_15139" WHERE "Name" = 'savio circuit' AND "Winning constructor" = 'itala'