Together, the following vendors supply most of the general business and financial databases. To find the information you require, you might have to search through several offerings from a number of services.

Supermarket vendors. The following four companies serve up a smorgasbord -- their databases cover such areas as business, science and technology, social science, and public affairs. The databases are generally bibliographic and do not contain full texts. Dialog Information Services Inc. (3460 Hillview Ave., Palo Alto, CA 94304, [415] 858-3785 or [800] 227-1927; in California, [800] 9825838) is the largest, with about 175 databases. System Development Corp., A Burroughs Co. (2500 Colorado Ave., Santa Monica, CA 90406, [213] 820-4111 or [800] 421-7229; in California, [800] 352-6689) and BRS (1200 Route 7, Latham, NY 12110, [518] 783-1161 or [800] 833-4707) each have more than 70 databases. Pergamon-InfoLine (1340 Old Chain Bridge Rd., McLean, VA 22101, [703] 442-0900 or [800] 336-7575) is the smallest, with about two dozen. Databases from these vendors cost from $35 to $300. There is some overlap among offerings, and each has unique databases.

Primarily full text. Mead Data Central (P.O. Box 933, Dayton, OH 45401, [800] 227-9597) offers about 100 business publications on its Nexis service. But, like other databases, it has some glaring omissions. Nexis, for example, does not cover The Wall Street Journal. (Mead also sells Lexis, which contains the text of federal and state court decisions.) Until recently, you had to rent a dedicated terminal from Mead for $55 to $150 a month in order to use the service. Now you can also buy a software package that allows you to access the database with an IBM Personal Computer. Nexis costs $30 to $90 per hour.

NewsNet (945 Haverford Rd., Bryn Mawr, PA 19010, [215] 527-8030 or [800] 345-1301) offers newsletters in more than 30 categories, such as publishing and broadcasting, energy, electronics and computers, farming, taxation, telecommunications, investment, and international business. The service costs a minimum of $24 per hour, double for 1200 baud. Dow Jones-News/Retrieval Service (P.O. Box 300, Princeton, NJ 08540, [609] 452-1511 or [800] 257-5114) contains edited highlights from The Wall Street Journal, as well as current stock quotations, Securities and Exchange Commission filings, and a few financial databases. Cost is $36 to $72 per hour, depending on database. (The cost doubles for 1200 baud.)

Primarily financial and economic. These two vendors deal mainly in numbers, rather than words. Data Resources Inc. (24 Hartwell Ave., Lexington, MA 02173, [617] 861-0165) offers its DataKits, preselected portions of the company's full databases for use with VisiLink, for $6 to $125 per worksheet, depending on the kit and the amount of information you request. I. P. Sharp Associates Ltd. (Suite 1900, Exchange Tower, 2 First Canadian Place, Toronto, Ontario M5X 1E3, Canada, [416] 364-5361) offers financial information, much of it targeted toward such specific industries as airlines and energy. Cost is $60 an hour, or $120 for 1200 baud. The company also sells MicroCom ($150), a software package to facilitate searching.

Several vendors offer special evening and weekend rates. NewsNet costs $6 per hour for the nighttime rate, 8:00 p.m. to 8:00 a.m. (eastern time). BRS has an abbreviated version of its regular service, called BRS After Dark. The cut-rate service is easier to use than the daytime version and has a number of business databases, including Management Contents; ABI/Inform (similar to Management Contents); Patdata, a database of U.S. patents; and Harvard Business Review Online. It costs from $8 to $16.50 an hour (including the long-distance telephone charges), in addition to an initial $50 sign-up charge and a $12 minimum monthly usage.

Dialog offers the off-hours Knowledge Index, which includes Magazine Index, with 400 popular magazines; National Newspaper Index, with full indexing of several major U.S. newspapers; and Microcomputer Index, covering several dozen microcomputer periodicals. It costs $24 an hour, with a $35 sign-up fee and no monthly minimum. And Dow Jones News/Retrieval costs only $9 to $54 per hour during off-hours.