The formula of gunpowder and the manufacturing method of weapons are recorded in General Theory of Jason Wu written by Ceng Gongliang and Ding Du in the Northern Song Dynasty. Wu Beizhi, Mao's anthology in Ming Dynasty, was also included in Military Capital.
They are gunpowder, Bao Puzi by Ge Hong in the Eastern Jin Dynasty, Dan Jing by Sun Simiao in the early Tang Dynasty, and the Secret Recipe of Taishang Shengdan written by an alchemist in the third year of Tang Yuanhe (808).