《资治通鉴·陈纪·陈纪二》
杨等人因为高演与长广王高湛地位很高，与皇帝又是亲属关系，恐怕他们对嗣主产生威胁，所以对他们心怀猜忌。
杨愔等以演与长广王湛位地亲逼，恐不利于嗣主，心忌之。
Yang and the others were suspicious of Gao Yan because he and Prince Changguang, Gao Zhan, were both high-ranking and related to the emperor, and feared that they would pose a threat to the heir apparent.