Mergent Online
A searchable database of over 10,000 U.S. public companies, over 18,000 international companies, and over 8,000 "dead stocks." There are comparable printed editions, some dating back to the 1950s, with historical income statements, balance sheets and cash flows.  See Reference Stacks HG 4961. M7.

EDGAR Database
A government database of SEC Filings dating back to the early 1990s, accessible to anyone off campus.

Older SEC Filings on Microfiche
Babson offers an archived microfiche collection of 10-Ks and Annual Reports to Shareholders plus Proxies and Prospectus: NYSE companies1972-1990 all other SEC companies 1978-1990.  Ask a librarian for help accessing this collection.