I love this book. It’s so well written that you could read it page after page and not get bored. It builds on how text retrieval works, how text is indexed. I wrote an algorithm that was taking about 2 seconds to compute a text piece. But when I implemented some of the techniques given here its processing time was reduced to 200ms. This is not a Natural Language Processing book but it has all the tricks you will need to work with real world applications that need to do text processing.