Article Info AuthorsDr.Ibraheem Mohammed Ali Al-NahellahDr.Mohammed AbdulAziz Al-MazroaDr.Abdullah Gainan AlzahraniVolume: 19Year: 2012Month: JulyIssue: 3Reference: Al-Nahellah I., Al-Mazroa M., Alzahrani AG., .Saudi Epidemiology Bulletin. 2012;19(3):.