bibliography. The listing of books is of ancient origin. Lists of clay tablets have been found at Nineveh and elsewhere; the library at Alexandria had subject lists of its books. Modern bibliography began with the invention of printing and at first consisted of "trade" bibliographies, i.e., lists of the publications of important publishing houses, comparable to those in the present-day Publisher's Trade List Annual, British Books in Print, and Books in Print. There have been efforts at universal bibilography: in 1545 at Zürich, Konrad von Gesner published his Bibliotheca universalis; in 1895 the International Institute of Bibliography was established at Brussels. There are national bibliographies, such as the Library of Congress Catalog and the British Museum Catalogue; subject bibliographies, such as Sabin's Dictionary of Books Relating to America; and lists of the works of individual authors. Bibliographies of rare and old books include Book Prices Current. The Cumulative Book Index is a monthly bibliography of books in the English language that cumulates annually. The Cambridge Bibliography of English Literature is useful for British publications, and the Bibliographic Guide to the Study of the Literature of the U.S.A., by C. L. Gohdes, for American works. The Bibliographical Index, which is cumulative, and World Bibliography of Bibliographies are useful compilations. The term bibliography is also used to describe books as physical objects and their production history, and has been expanded to include nonprint media such as microfilm.