《资治通鉴·唐纪·唐纪四十七》
李泌说： 安西、北庭地区，人们生性骁勇剽悍。该地控制着西域五十七个国家以及十个姓氏的突厥人，又能分散吐蕃的声势，使吐蕃不能合兵一处而向东侵犯，怎么能轻易地让给他们！
李泌曰： 安西、北庭，人性骁悍，控制西域五十七国及十姓突厥，又分吐蕃之势，使不得并兵东侵，奈何拱手与之！
Li Bi said: The people in the Anxi and Beiting areas are naturally brave and fierce. The region controls 57 states in the Western Regions and ten surnames of Turkic people and can divide up the prestige of Tubo, preventing Tubo from uniting all of its soldiers and invading the east; how could we easily cede it to them!