<p>Ideally, an historian, if he is to acquit his task, must know the total range and types of sources available to him, in and around the topic of his enquiry. Knowing what his colleagues have published is essential. However, it is hardly possible to compile, and keep up to date, a full bibliography. Selection is both subjective and arbitrary; and a selection of books, articles and manuscripts is no exception.</p> <p>Nonetheless, a serious researcher will attempt to make a survey of all the material, archival and secondary, which may conceivably be relevant to his topic. Geoffrey Elton has described this as "a broadfronted attack upon all the relevant material". This is of primary importance to historical scholarship. First and foremost, it is pointless to duplicate work once all the major issues and questions involved, have already been thrashed out by other historians. It has been said that history is an endless debate. This is true. However, debating historians must have something to say. An historian tackling a hackneyed topic, must either have discovered new evidence or must advance a novel interpretation of existing evidence.</p>