From its first edition the purpose of Walford has been to identify and evaluate the widest possible range of reference materials. No rigid definition of reference is applied. In addition to the expected bibliographies, indexes, dictionaries, encyclopaedias, directories, a number of important textbooks and manuals of general practice are included. While the majority of the items are books, Walford is a guide to reference material. Thus periodical articles, microforms, online and CD-ROM sources are all represented. In this volume a particular effort has been made to improve coverage of the latter two categories. To be of manageable proportions a guide such as this must inevitably be selective. Most major reference tools are included, whenever originally published, provided they remain useful. New material, often overlooked, is also covered in some depth. The geographic scope is international, but with an emphasis on English-language material. A special effort has been made to ensure that the output of small and specialist publishers is not neglected. Entries in Walford follow a subject arrangement based on the Universal Decimal Classification Medium Edition of 1985 (BS1000M). Subject access for users unfamiliar with UDC can be gained either by checking the contents page to find the relevant section and then browsing through the entries which are subdivided by form, place etc, or by using the subject index. Terms in this index are generated by the classification numbers given to each entry. References in the accompanying author/title index are to entry rather than UDC or page numbers, each record being assigned a consecutive number. Full instructions on the structure and use of the indexes can be found in their introduction. Individual entries in Walford are nearly always based on the examination of the actual item and include full bibliographic detail, ISBN and, if in print, the price when it can be ascertained. Brief critical annotations are provided in most cases, giving summary publishing, outline of contents, comparison with other works, especially notable features and a brief general assessment of overall value, often illustrated by quotations from or references to reviews. As with volumes one and two, a thorough revision has been undertaken for the fifth edition of volume three. Many entries have been dropped to make way for new material, while those that have been retained have been revised and updated where necessary. The main classification change affecting this volume since the previous edition is the merger of Class 4, Language, with Class 8, Literature, to form an expanded Class 8 in which these two closely related subjects - formerly separated by Class 7, Arts - are brought together, with Language (at 8.0/809) preceding Literature (at 82/89). Proper names, including both personal and geographical names, move from volume 2 to join this volume at 801.31l. The ever-increasing output of reference material, particularly from US publishers, has necessitated strict selectivity but coverage of subject areas has been expanded to reflect increasing interest. These include, in Class 0, online and CD-ROM databases, in Class 7, cinema, television, video and sound recording, and, in Class 8, African, Commonwealth and Spanish-American literatures. A notable feature of recent literary reference publishing, which is reflected in Class 8, has been the proliferation of works on women and ethnic minority writers, both general in scope and related to specific national or regional literatures. Works on genre fiction, another area of increasing output, have been brought together at 82-311/39 rather than scattered under the national literature.