You will probably already have a large number of texts that are relevant to your study.  You can also ask colleagues and others in your social network if they know of papers relevant to your topic.  You may also find studies through a chance discovery.

In the exercise 'Assemble a review group / advisor group' you made a list of academics working in the area, practitioners working in the field, librarians / information scientist, practitioners or policy makers.  You may wish to contact these people to help you locate studies.  This can be particularly helpful for identifying working papers and unpublished material. 

If you receive a large number of relevant papers through your social network you may want to reflect on the reasons why you didn't pick up these studies through the protocol driven search or via snowballing.  Are you using appropriate keywords? Are you searching appropriate databases?

Make a list of the articles that you find by means of personal knowledge and include this table in your protocol/plan:

List of articles	Number of papers
Previously known to the reviewer:
1. 2. n.
Located through personal contacts and academic networks
1. 2. n.
Located through serendipitous discovery
1. 2. n.
Total number of articles located through personal knowledge

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