Article Info AuthorsDr.Mohammed Hussain Hassan Al-OmriDr.Mohammed AbdulAziz Al-MazroaDr.Sami Saeed Saeed AlMudarraVolume: 18Year: 2011Month: JulyIssue: 3Reference: Al-Omri M., Al-Mazroa M., AlMudarra S., .Saudi Epidemiology Bulletin. 2011;18(3):.