CREATE TABLE table_203_739 (id DECIMAL, "rank" DECIMAL, "nation" TEXT, "gold" DECIMAL, "silver" DECIMAL, "bronze" DECIMAL, "total" DECIMAL)

in the 2003 summer universiade , which three countries had at least 18 bronze medals ?
SELECT "nation" FROM table_203_739 WHERE "bronze" >= 18
SELECT "nation" FROM "table_203_739" WHERE "bronze" >= 18