Page "Sun Tzu" Paragraph 6

Shiji claims that Sun Tzu later proved on the battlefield that his theories were effective ( for example, in the Battle of Boju ), that he had a successful military career, and that he wrote The Art of War based on his tested expertise.

However, Zuo Zhuan, an earlier historical text which provides a much more detailed account of the Battle of Boju, does not mention Sun Tzu at all.