Tools VI/Information retrieval: Engineer´s source guide: Researching a complex problem or looking for the answer to a nagging technical question? This directory may help

The following is a guide to some of the sources where researchers, or the casual questioner, can find the data they need in a number of engineering and engineering-related areas. In addition to the specific categories listed, information on a variety of technical subjects is available from the Engineering Societies Library and from Engineering Index, both at 345 East 47 Street, New York, N.Y. 10017. For tabulations of reference materials, literature guides, retrieval services, and abstracting and indexing services, the reader is referred to Madhu-Sudan Gupta´s Spectrum article, ¿Where to find it when you need it¿ (May 1974, pages 72¿77). And elsewhere in this issue (pages 68¿71), Oscar Firschein tells you how to keep up to date with ¿On-line reference searching.¿