《资治通鉴·唐纪·唐纪六十二》
孙俦说不用增加多少，只是大同军的兵力少，只要得易定一千人援助就足够了。 
俦言不须多益兵，唯大同兵少，得易定千人助之足矣。 
Sun Chou said that not many more were needed. Only the Datong army was short on troops, and if it could be supported by one thousand people from Yiding, it would be enough.