ReferenceUSA The ReferenceUSA database contains detailed company descriptions, corporate family trees, management directories, and competitor information for more than 20 million U.S. businesses. ReferenceUSA enables users to conduct a custom search to help identify and compare companies. Custom search options include business type, geography, business size and ownership type. Use to generate lists of healthcare companies in a zipcode radius, if you decide to look at Businesses as potential customers/partners.