Instruct: Classify Amazon reviews into positive or negative sentiment
Query: amateur go player

Most people seem to recommend Volumes 2, 3, and 4 (especially 3 and 4) of this series. Volume 1 is too easy.Amazon apparently does not carry anything except Volume 1, but all of the volumes can be ordered online from Kiseido. If you are interested in this book, also consider Get Strong at Tesuji and One Thousand and One Life-and-Death Problems. Check out David Carlton's internet go bibliography for more info.