- 1). Reverse search for a company at an online business directory such as Superpages. Use the "Advanced Search" and enter the information you have -- a phone number or address -- into the relevant search fields to see what companies match that information.
- 2). Use a specialty business directory like Dun & Bradstreet. You can reverse search on an address or phone number and can also search on a company's DUNS number -- a unique identifier widely used by businesses.
- 3). Consult a librarian. Libraries generally have access to specialty directories such as ReferenceUSA that are not otherwise available to the public. A librarian can help you reverse search this database for company listings.
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