Why use a directory?
Directories can help you find out if a company is public or private. Why does this matter? U.S. public companies which trade on the stock market are required to file documents regularly with the SEC (Securities and Exchange Commission). Information on private companies can be much harder to find. Directories, articles or news stories may be the main sources of information for some private companies.
Note: most of the resources listed here are available on-site only, at the Science, Industry and Business Library (SIBL).
Note: Some library databases have been made accessible for temporary remote access during the pandemic while the libraries are closed.
Now accessible with a NYPL library card: Reference Solutions ( Formerly titled Reference USA ),