《资治通鉴·汉纪·汉纪三十二》
积弩将军冯、车骑将军宗歆同守邑，二人因争权而互相攻打。冯于是杀了宗歆，并乘机反过来攻打邓禹。
积弩将军冯愔、车骑将军宗歆守栒邑，二人争权相攻，愔遂杀歆，因反击禹，禹遣使以闻。
Ji Nu General Feng and General of the Chariots and Cavalry Zong Xin defended the same city. They started fighting each other due to a power struggle. Feng ended up killing Zong Xin and took this opportunity to turn against Deng Yu.