Jafferbhoy, Sadaf, Panas Symeonides, Melanie Levy, and Muhammad H. Shiwani. 2013. “Chronic Umbilical Discharge : An Unusual Presentation of Endometriosis”. Sultan Qaboos University Medical Journal 13 (1):143-46. https://journals.squ.edu.om/index.php/squmj/article/view/1767.