The IIRE is home to an unique collection of texts on the history of the social movement and radical social theory, with a special focus on the history and thought of the Fourth International. Our library consists of over 25,000 books and several thousand periodicals. Most of the books are in one of the IIRE's three working languages, English, French and Spanish; but there are also significant collections in German, Portuguese and Italian, with smaller collections in several other languages.