Q. What is the professional business literature?

On one level the "professional business literature" is whatever you professor wants it to be. I can tell you what I think is meant by that, but your professor if the ultimate authority (for this semester, anyway :) )

I would use either journals (peer-reviewed, scholarly publications) or trade publications (non-academic publications that provide quality information for a particular occupation or industry).

I would avoid websites, popular magazines, and newspapers. With that said, the Wall Street Journal is a newspaper, and a good source. Some local business information might only be able to be found in a local newspaper.

The definition could be fluid, based on a topic, which is why I defer to your professor.

It is easy to find journals and trade publication using our databases. The link for a menu of our business databases is: http://libguides.css.edu/az.php?s=134

Business Source Ultimate allows you to search on your topic and then limit the results to journals or trade publications. If the text of the article is not available you can request it through Interlibrary loan.

Good luck with the semester.