《北史·列传·卷二十九》
杨素性情疏懒而又好计较，大事小事都放在心上。朝臣之间，他只推崇高赹，敬重牛弘，厚待薛道衡，看待苏威好像不存在一样。
素性疏而辩，高下在心，朝贵之内，颇推高颎，敬牛弘，厚接薛道衡，视苏威蔑如也。
Yang Su has a lazy and cautious temperament, and he takes both big and small matters to heart. Among the ministers of the court, he only admired Gao Jiong, respected Niu Hong, treated Xue Daoheng kindly, and treated Su Wei as if he didn't exist.