Parsing Techniques — A Practical Guide, is simply one of the best computer science books i’ve read, if not just the best book on the theory and practice of parsing.
It’s a magnificent tome of work, broad in scope and detailed in depth, with at least 400 references in print, and an astounding 1600 references online. Accessible, clear, and thorough, it is of use for both the novice and the expert.
If you’ve ever been a little curious about parsing, or wanted to improve on a technique, this is the book for you — it is the definitive work on parsing.