From Dr. Ford's assignment:
Your research should focus on scholarly sources and those produced by reputable interest groups, research organizations, NGOs (non-governmental organizations), think tanks, and state/national government sources. You may find the occasional source mentioned in a media story, but you should find the original report or data described, as opposed to relying on the media article. Your annotated bibliography should include at least 10 sources. You may choose either MLA or APA for your citations, just be consistent.
The US government (as well as many governments around the world and international governing bodies, such as the United Nations) produces a vast amount of information. Some examples of government information include: legislation, case law, research and policy papers, census data, consumer publications, and much, much more.
Unless it is classified, most government information is freely available on the web. You can find much of it through the GovInfo portal.
GPO's official system for Federal information from all three branches of the U.S. Government. Provides free online access to official Federal Government publications.
"Grey literature" refers to stuff that is rigorous and well-researched, but doesn't neatly fit into the major categories of peer-reviewed articles and scholarly books.
Examples of grey literature:
Whether or not grey literature will be useful and appropriate depends on your information need and where the information is coming from.