Statistical Universe Index to Federal statistical publications, including the Statistical Abstract of the United States. Statistical Resources on the Web Excellent source from the University of Michigan Document Center. CenStats Provides easy access to several popular Census Bureau databases.
Some information is free.
Ask at Reference Desk for user ID and password if you need to login. U.S. Census Bureau Home Page Source of demographic and economic information. SIC Codes Search the 1987 SIC Manual by number or keyword. The new system replacing SIC codes. This web page maintained by Linda London, Reference Librarian, Central Missouri State University, Warrensburg, Missouri.