Annually published since 1930, the International Bibliography of Historical Sciences (IBOHS) is an international bibliography of the most important historical monographs and periodical articles published throughout the world, which deal with history from the earliest to the most recent times. The IBOHS is thus currently the only continuous bibliography of its kind covering such a broad period of time, spectrum of subjects and geographical range. The works are arranged systematically according to period, region or historical discipline, and alphabetically according to authors names or, in the case of anonymous works, by the characteristic main title word. The bibliography contains a geographical index and indexes of persons and authors.