Rozina Memon’, Saira Parveen2, Afra Rehman , Yasmeen Joyo4, Mehnaz Akram Shaikh5, “ Diagnostic Accuracy of Ultrasound in Determination of Chorionicity of Twin Pregnancies at PMCH Nawabshah”, JPUMHS, vol. 9, no. 4, pp. 50–54, Dec. 2012.