《旧唐书·本纪·卷十二》
伊西、北庭节度使、观察使李元忠可以任北庭大都护，四镇节度留后郭昕可任安西大都护、四镇节度使、观察使。 
伊西、北庭节度观察使李元忠可北庭大都护，四镇节度留后郭昕可安西大都护、四镇节度观察使。 
Lixi, Beiting Jiedushi, and Guanzhanshi Li Yuanzhong can be appointed as Beiting Daduhu, and Guo Xin, the Jiedushi Liuhou of the four towns, can be appointed as Anxi Daduhu, Jiedushi of the four towns, and Guanzhanshi.