Narrative reviews are vulnerable to the selection bias of the author; it is all to easy to review only articles that support a particular outcome or perspective. Systematic reviews attempt to control this threat of bias by using a documented and reproducible method for selecting articles that are relevant to a specific question or problem. Systematic reviews aim for thoroughness and are time-consuming and labor-intensive enterprises that are usual carried out by research teams. This assignment will not produce what you could call a systematic review, but it will introduce you to some systematic searching methods and citation management technologies that are essential for carrying out more rigorous literature research. The requirements of this assignment are informed by the guidelines for systematic reviews found in the Cochrane Handbook, the PRISMA statement, and other standard references for systematic review methodology.