《资治通鉴·唐纪·唐纪十二》
于志宁与左庶子张玄素多次上书直谏，太子暗中派人杀他们，没有成功。
志宁与左庶子张玄素数上书切谏，太子阴使人杀之，不果。
Yu Zhinong and left shuzi Zhang Xuansu repeatedly submitted memorials to criticize, the Prince secretly sent people to kill them, but all failed. 