Working papers are helpful when you look for the most recent research on a topic, and is one of the most common sources in finance and economics literature.
Some working papers are intended to be included in scholarly journals, and later become available through searching business article databases such as ABI/INFORM or Business Source Complete, but others, especially that are published by government bodies are available as a series of working papers.
A working paper is often a brief summary or preliminary report of original research.
You can find the working papers from:
1. the author's website
2. institutional repositories (e.g., Harvard Business School Working Papers )
3. government bodies (e.g., National Bureau of Economic Research)
4. subject repositories (e.g., SSRN), or
5. search engines like Google or Google Scholar