Instruct: Classify Amazon reviews into positive or negative sentiment
Query: A bit pricey, but great book!

I knew absolutely nothing about oil and gas production before opening this book. It did everything I'd expect an entry-level textbook to do. I have to admit, the price was a bit much. I had difficulty parting with the money. But the book is very well done and I'd recommend it to anyone looking for an easy to follow introduction to oil and gas production.