《旧唐书·列传·卷三十六》
这时戴至德、张文馞兼右庶子，与右庶子肖德昭一同辅弼太子，太子多疾病，一般政务都由戴至德等定夺。
是时戴至德、张文瓘兼左庶子，与右庶子萧德昭同为辅弼，太子多疾病，庶政皆决于至德等。
During this period, Dai Zhide, Zhang Wenhu, and Xiao Dezao served as deputy crown princes and assisted Crown Prince Li Hong, who often fell ill.  The three deputy crown princes often made important decisions on his behalf. 