Viral and non-viral risk factors for non-Hodgkin’s lymphoma in Egypt: heterogeneity by histological and immunological subtypes - Lenka Goldman; Sameera Ezzat; Nadia Mokhtar; Amany Abdel-Hamid; Nathan Fowler; Iman Gouda; Soheir Abdel Latif Eissa; Mohamed Abdel-Hamid; Christopher A. Loffredo (Cancer Causes & Control, 2009)