Instruct: Classify the given Amazon review into positive or negative sentiment.
Query: Great book with important concepts

Although I knew that I could have a free .pdf (and I do have it) from the internet, I wanted to get this book in text. I know that I will be studying and meditating on the principles and axioms in here for some time to come. I bought it in print mostly so I could try to proselytize with it haha. Not seriously, but I show it to my friends to try and interest some of them, and I have managed to interest a couple. Hopefully, they will seek out more knowledge after reading this, just like I have.