《旧唐书·本纪·卷十九》
二月初二，庞勋急攻泗州。派部将李员进城去见刺史杜忄舀说： 庞大人知道中丞出身于名门望族，不敢使部下的士兵有失礼的行为，只要打开城门，就让城里的百姓存活下来，大人不要产生怀疑。 
二月己丑，庞勋急攻泗州，遣牙将李员入城见刺史杜慆曰： 留后知中丞名族，不敢令军士失礼，但开城门，令百姓存活，无相疑也。 
On the second day of February, Pang Xun urgently attacked Sizhou. He sent his deputy general Li Yuan to enter the city to see the magistrate Du Xinyu and say: Lord Pang knows that the governor is from a famous family and dares not let his men behave rudely. As long as he opens the city gates, the people in the city will survive. Please do not doubt him.