《魏书·列传·卷八十七》
李氏与牧犍的姐姐合谋用毒药杀害武威公主，皇帝派医生带上解毒药乘驿车驰往急救，使公主得以痊愈。
李与牧犍姊共毒公主，上遣解毒医乘传救公主得愈。
Li and Mukgan's sister conspired to murder Princess Wuwei with poison. The emperor sent a doctor to carry the antidote on a fast horse to rush to the emergency room, and the princess was able to recover.