《旧五代史·其它·僭伪列传二》
到周世宗即位后，刘崇又向契丹请求军队，以图谋寇犯中原，契丹派遣将领杨衮会合刘崇兵力，大举进攻迫近潞州。
及周世宗嗣位，崇复乞师于契丹，以图入寇，契丹遣将杨衮合势大举，来迫潞州。
After Zhou Shizong ascended to the throne, Liu Chong asked the Khitan for troops again, in an attempt to invade the Central Plains The Khitan sent General Yang Gun to join Liu Chong's army to launch a massive attack and approach Luzhou.