《资治通鉴·唐纪·唐纪十三》
等到李承乾谋反事败露，秋季，七月，辛卯，又将杜正伦降职为交州都督。
及承乾败，秋，七月，辛卯，复左迁正伦为交州都督。
When Li Chengqian's plot was exposed, in the seventh month of autumn, Xinmao, Du Zhenglun was demoted again to the post of governor of Jiaozhou.