Comparison of Cervical Volume and Cervical Length to Predict Preterm Delivery by Transvaginal Ultrasound - Dilek, Talat Umut Kutlu; Gurbuz, Ayfer; Yazici, Gurkan; Arslan, Murat; Gulhan, Sitki; Pata, Ozlem; Dilek, Saffet (American Journal of Perinatology, 2006)