Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Bad book, select much better books by Laithi or Oppenheim

Terrible book. Would recommend books such as Oppenheim's Signals and Systems or Laithi's Linear Systems and Signals.A very good book on the subject that is easy to follow as a quick guide is Signals and Systems Made Ridiculously Simpleby Zoher Z. Karu.Stay away from Roberts book if at all possible. Confuses even easy to understand topics.