Raven Used Books, Cambridge

###In Focus: Raven Used Books * **Neighborhood:** Harvard Square * **Number of books:** about 15,000 at any given time * **Subject-area specialties:** philosophy, history, political theory, anthropology, religion, literature * **The owner:** John C. Petrovato, who’s been selling books for more than 20 years * **Best reason to shop here:** most books sell for 50%–80% off their cover price * **Fun fact:** A set-design crew bought the store’s entire stock of physics books to use in the 2016 _Ghostbusters_ movie.