《旧唐书·列传·卷八十三》
李晟向内围攻郑景济，在外与朱滔等作战，一天几仗，从正月直到五月。
晟内围景济，外与滔等拒战，日数合，自正月至于五月。
Li Sheng attacked Zheng Jingji from inside and fought with Zhu Tao and others outside. There were several battles a day from January to May.