Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Questionable, but worth your time

The origins of Dim Mak and its supposed effectiveness are extremely questionable. But, Erle Montaigue does seem to be the authority in this controversial subject, and I do believe this is the definitive guide.The chapter about Fa-Jing is very useful for Chen Taichi practitioners. Modern Yang style, which is supposed to be the roots of Dim Mak, has lost all the Fa-Jing movements.