This 30th volume of American Reference Books Annual (ARBA) covers 1,578 books and CD-ROMs published in 1998 (with some from 1997 that were not included in the previous volume). The basic purpose of ARBA is to provide comprehensive coverage of English-language reference books published or distributed in the United States or Canada during a single year. Dictionaries, encyclopedias, indexes, directories, bibliographies, guides, concordances, atlases, gazetteers, are reviewed in each volume. General encyclopedias that are updated annually, yearbooks, almanacs, indexing and abstracting services, and other annuals or serials are reviewed at intervals of 3 to 5 years. New editions of reference books are reviewed with comparisons to older editions. Titles produced for the mass market in the areas of collectibles, travel guides, and genealogy receive selective coverage. The book is organized in four sections--general reference works, social sciences, humanities, and science and technology. Within the sections, chapters are arranged alphabetically by subject. Signed reviews by subject specialists describe the contents, scope, purpose, and intended audiences of the titles, and most make special note of positive and negative elements, quality of writing, and how a book compares to similar titles. Includes author/title and subject indexes. (AEF)