《旧五代史·后唐·列传十七》
三年，东西两川交战，明宗担心如合并到一人手中，朝廷更难制服，密诏要王思同分析形势，乘两川有间隙用兵，事情还没实行，董璋就失败了。
三年，两川交兵，明宗虑并在一人，则朝廷难制，密诏思同相度形势，即乘间用军，事未行而董璋败。
For three years, the East and West Sichuan armies had waged war against each other. Emperor Mingzong was concerned that the situation would become difficult for the imperial court to control if the armies were to be merged into one. He secretly decreed for Wang Sitong to analyze the situation and take advantage of the divide between the two Sichuan armies to wage war. Before he could act, however, Dong Zhang was defeated.