《旧唐书·本纪·卷十二》
兼度支使杜佑道 ：现在各道用兵打仗，每月耗费度支钱一百多万贯，假若获得五百万贯，才可以支给数月。 
判度支杜佑曰： 今诸道用兵，月费度支钱一百余万贯，若获五百万贯，才可支给数月。 
Du You, who concurrently served as the Dushi of Duzhi, said: now each dao is spending over a million guan per month on the war. If the government could acquire five million guan, it would be enough to fund the war for several months.