Problems in Diagnosis and Treatment of Retrorectal Tumors: Our Experience in 50 Patients - Maddah, Ghodratollah; Abdollahi, Abbas; Etemadrezaie, Hamid; Ganjeifar, Babak; Gohari, Behnaz; Abdollahi, Mohsen; Hassanpour, Masoumeh (Acta Medica Iranica, 2016)