CINAHL is an excellent tool to help you carry out a comprehensive search for relevant references. Remember you will not have access to all articles as full text.
Medline is an excellent tool to help you carry out a comprehensive search for relevant references. Remember you will not have access to all articles as full text.
The Cochrane Library is a database of systematic reviews commisioned by the Cochrane Collaboration. The Cochrane Library also contains information about controlled trials and is updated every month.