For people interested in Dr. Perelman, this is one of the fewest published. It is an indirect research through impressions from people who met Perelman, but it would be dissapointing if someone seeks a complex description by the own personage. The last interpretations about the behaviour of Perelman by Mashga Gessen are very keen of being critized and dissapointingly dubious. Generally speaking, it is a useful book to understand the background where Perelman appears but more authorative and respectful books are warranted in terms of biography. Dr. Perelman would be probably one of the our most important genious and honest figures.