Introduction to Grey Literature
Grey literature is all of that information that is not published in books or journals. Before the web, it was much harder to locate, but any Google search will have you swimming in it in no time.
This guide will walk you through the various types and the reasons you may want to seek them out, as well as provide links to help you find what you need.
Many new ideas come to conferences long before they're published in journals. You will want to check the archives of any major conference in your discipline.
Communication Sciences and Disorders
Physical Therapy - APTA does not have an online archive
Online trial registries may include results of completed but unpublished clinical trials.
The United States government loves to collect data. These are just a few of the places they make it available to us. If your topic doesn't fall under the domain of one of these areas, another agency undoubtedly covers it.
Advocacy and Professional Organizations
The are an abundance of health related advocacy organizations, many of which collect data and relevant information for their constituencies. If you do not already know of the advocacy organizations related to your area, these lists might help you find them.
If you'd like to take a more international perspective on your topic, be sure you check data and white papers coming out of these international organizations (and any others that might be related to your topic).