1. The Cochrane Collaboration; UKCC (Bahrain Branch); Box 25438 Awali Bahrain
2. Leiden University Medical Center; Department of Dermatology; PO Box 9600 B1-Q Leiden Netherlands 2300 RC
3. University of Plymouth; Peninsula Dental School; The John Bull Building, Tamar Science Park, Plymouth UK PL6 8BU
4. Cardiff University School of Medicine; Institute of Primary Care & Public Health; 3rd Floor, Neuadd Meirionnydd, Heath Park Cardiff UK CF14 4YS
5. AMA International University; College of Medicine; Salmabad Bahrain