BHO is a database in English on the history of the printed book and libraries. It contains titles of books and articles on the history of the printed book worldwide. It is based on ABHB, the Annual Bibliography of the History of the printed Book and Libraries. Subjects covered by BHO correspond with those of ABHB: all scholarly valuable books and articles relating to the history of the printed book and libraries, and to book production, distribution, conservation, description and analysis. Also included are articles referring to the history of the arts, crafts, techniques, and equipment in relation to books, and to the book and library in their economic, social and cultural environment. BHO contains all ABHB entries from 1990 onwards.