Everson, B. (2012). Why? [photo]. CC. Retrieved from http://www.flickr.com/photos/editor/6698208975/
Consider limiting to certain Primary Source types such as "Controlled Clinical Trial", "Case Study/Report" "Randomized Controlled Trial" and or other article types to seek the Primary Source type of interest.
For help searching databases for primary sources, contact your Librarian!
Before you begin searching in large article databases such as CINAHL or PubMed, be sure to create an effective search strategy to obtain optimal results.