Sun Bin
There are other historical writers associated with Chinese military classics whose writings may have contributed to the "Methods of the Sima". Because the writer Sun Bin was a relative of Sima Rangju, and because Sun Bin served Qi as a military advisor in the fourth century BC, around the time that the "Methods of the Sima" was compiled, some scholars theorize that the writings of Sun Bin may have contributed to the "Methods of the Sima". Because all sources identify "the Methods of the Sima" with the state of Qi, and because Jiang Ziya was enfeoffed as the Duke of Qi shortly before his death, other scholars believe that the tradition of Jiang Ziya's writings may have contributed to the book's compilation. Because the origins of the book are enigmatic, the authorship of "the Methods of the Sima" cannot be either proven or refuted.