Wujing Zongyao
Parts of the "Wujing Zongyao" were copied from older sources; historian Ralph D. Sawyer calls it "essentially a cut-and-paste job", containing many passages from earlier classical military writings whose original authors are left unidentified, a common practice at the time. During the Song dynasty, the "Wujing Zongyao" was appended to two other books: the "Xingjun xuzhi" and the "Baizhan qifa", both written by anonymous authors.