These can sometimes be the only place to find information on small private companies. The information given may be only name and address or may include a total sales figure or number of employees. MacRae's Blue Book . 2 vols. MacRae's Blue Book, 1893- . It includes corporate, trade name, and product classification indexes.
Information is very basic.
Thomas Register of American Manufacturers also Thomas Register Catalog File . Thomas Publishing, 1905- . The most comprehensive list available of manufacturing firms and specific products in the U.S. and Canada. The Internet version offers many of the same features in an online searchable format but covers fewer companies. U.S. Industrial Directory .