Using PRISMA 2

Step 3: Additional sources If you have identified articles through other sources than databases (like manual searches through reference lists of articles you have found, or search engines like Google Scholar or Mednar), enter the total number of records in the box on the top right of the flow diagram.

Step 4: Remove all duplicates To avoid reviewing duplicate articles, you need to remove any articles that appear more than once. You will need to go through all the records or articles you have found in the database and manually remove any duplicates. This is not easy to do if you have a large number of articles at this point. In this case you may want to export the entire list of articles to RefWorks (including citation and abstract) and remove the duplicates there. 
Enter the number of records left after you have removed the duplicates in the second box from the top.

Creative Commons Licence
SMILE using PRISMA by Marion Kelt and Larissa Kempenaar, GCU and The PRISMA Statement is licensed under a Creative Commons Attribution 4.0 International LicenseBased on a work at http://www.prisma-statement.org/index.htm.