《资治通鉴·陈纪·陈纪三》
兖州刺史毕义云写信给高元海，信里议论时局，高元海在进宫时，不知不觉地把信遗失了。
兗州刺史毕义云作书与高元海，论叙时事。元海入宫，不觉遗之。
Bi Yiyuan, the governor of Yanzhou, wrote a letter to Gao Yuanhai, discussing the current situation. When Gao Yuanhai entered the palace, he had left the letter unconsciously.