Answer

Working Papers can be defined as "an official report produced by a group of people who are studying a particular problem or situation, especially in order to give suggestions or suggest improvements".

Go to the Virtual Business Library's Journals/Newspapers section for links to useful resources including links to the following suggested resource. You may also be interested in material under the Case Study section. 
 

ABI/INFORM: Provides full-text journals, dissertations and working papers.  Go to the Source Type and choose Working Papers.

For information on the Stern School Working Papers, go to the Stern School Department of Economics page, Working Papers, 1992 to date. 

You may also want to review The National Bureau of Economic Research website, NBER Working Papers as well as Google Scholar, Working Papers.