Number 4, on corner positions, is accessible to people not able to read Japanese. It is a dictionary-like treatment of life-and-death in corner positions that often occur in real games. This differs from most tsumego books in which the problem positions are mostly contrived and would not likely happen in actual games. I have numbers 2, 3, 4, 6, and 7 from the list on the main page. Except for number 4 they have a high ratio of text to diagrams, and the text is not simple. One useful feature of these books, except for number 4, is the example games illustrating the concepts discussed.--Bob McGuigan