The book ''CHIN NA FA'' was written by Liu Jin Sheng in collaboration with Zhao Jiang. The first edition of the book was issued in July of 1936 as a manual for the Police Academy of Zhejiang province. The book was printed by the publishing house Shan Wu in Shanghai. ''...If you are in command of this technique, you can sway the destiny of the enemy. You can kill your enemy, cause unbearable pain, tear his muscles and sinews, break his bones or make him unconscious for some time and completely disable him to resist. Even a woman or a physically weak man who mastered this technique can curb a strong enemy. This technique demands deftness and skill, not brute force. It is necessary to train oneself daily to make the body flexible and nimble, but ''hardness'' must be hidden inside this ''softness.'' /Author Liu Jin Sheng. The Police Academy of Zhejiang province. 1-st of May of the 24-th year of the Chinese Republic (1935)/