Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Tedious Perturbations

This is an expanded version of an earlier text by the second author (Cole). The latter was clearly written, to the point, and a useful resource. The same cannot be said of this book. It obscures the ideas underlying perturbation methods with excessive detail on problems of marginal interest. It also, oddly, fails to adequately explain a fundamental method such as multiple scales. Their explanation of how and why scales are selected misses the point completely. This is odd as the authors made contributions to the early development of this method and, as pointed out by the other reviewer, this is the main focus of the book. I would not recommend this book, even as a second or third text on the subject.