NBER is a well-respected private, non-profit research organiztion founded in 1920. The full text of all NBER papers issued since June 1973 is available online. For help with papers published earlier, check with a reference librarian.

The Center for Economic Studies (CES) both maintains data files and publishes Discussion Papers.

EconPapers provides access to RePEc, the world's largest collection of on-line Economics working papers, journal articles and software.

Coverage: varies. A comprehensive index to Federal Reserve economic research.

Publications of the International Monetary Fund.

The OKN contains World Bank published books from 2009-2012, all World Development Reports (WDRs) since 1978, Policy Research Working Papers (PRWP) from 2009-2012, Economic and Sector Work (ESW) studies from 2009-2012, journal articles from 2007-2010 published in World Bank Economic Review (WBER) and World Bank Research Observer (WBRO) (two journals published by Oxford University Press on behalf of the World Bank), content in languages other than English, and World Bank Group Annual Reports and Independent Evaluation Studies.