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This book is informative but a bit disjointed, in that its sometimes is a text book, and sometimes a story book. The author undoubtedly is the expert on his subject but he isn't a writer. He will offer a theory or priciple then tell you a real life story to illustrate it. He tends to lay out a story then say, "see thats how it works" but often he adds to the theory he is discussing, conclusions that he alone can make that the reader cannot see so clearly. This is confusing but if you study it hard enough most times the connection becomes clearer but not slways. I learned a lot from the read, so it was a useful book.