This latest edition of the first volume of the three-volume Walford's Guide to Reference Material provides excellent coverage of reference materials in sciences and technology. The editors have added over 1000 new sources (which now total 7,007), have expanded coverage of subjects of current interest (such as conservation and microcomputers), and have added an index of online databases. The book's primary organization continues to be by Universal Decimal Classification (UDC). Citations are annotated and often include quotations from reviews. In addition to the online resources index, there are author/title and subject indexes. This volume is the most currently comprehensive resource on science and technology in print. It compares most readily with Eugene Sheehy's Guide to Reference Books (ALA, 1986. 10th ed.) and the supplement, Guide to Reference Books: Covering Materials from 1985-1990 (Professional Reading, LJ 6/15/92). Both Walford's and Sheehy are excellent guides and cover the same areas of science (except Walford's places anthropology among the sciences) and include sources published mostly in North America and Western Europe. Walford's citations are more current by about two years; the titles covered were published as recently as 1992. It is also much more current, comprehensive, and usable than Ching-Chih Chen's outdated Scientific and Technical Information Sources (MIT Pr., 1987). One criticism is that the quality of the binding may not be adequate for the size of the text. With its expanded subject coverage, inclusion of online resources, and currency, Walford's still belongs on every reference and professional reading shelf.-Joyce Ogburn, Yale Univ. Lib., New Haven, Ct.