《资治通鉴·汉纪·汉纪四十六》
当初，张奂因被指控为梁冀的旧属而遭到免官和终身不准再出来做官的惩罚，他的故交老友没有一个人胆敢为他说话，只有皇甫规向朝廷推荐张奂，前后一连呈递了七次奏章，朝廷因而任命张奂为武威郡太守。
初，张奂坐梁冀故吏，免官禁锢，凡诸交旧，莫敢为言；唯规荐举，前后七上，由是拜武威太守。
In the beginning, Zhang Huan was accused of being a loyal follower of Liang Ji and was dismissed from his position and forbidden from ever being an official again. None of his close friends dared to speak up for him, except for Huangfu Gui, who recommended Zhang Huan to the court seven times. The court therefore appointed Zhang Huan as the Governor of Wuwei.