《魏书·帝纪·卷四》
刘义隆的白水太守郎启玄率军救助杨文德，皮豹子迎战，大破敌军，启玄、文德逃归汉中。
义隆白水太守郎启玄率众救文德，豹子逆击，大破之。启玄、文德走还汉中。
Liu Yilong's chief of Baishui, Lang Qixuan, led his army to rescue Yang Wende. Pi Baozi fought against them and defeated the enemy. Qixuan and Wende fled back to Hanzhong.