Prediction of Spontaneous Onset of Labor at Term: The Role of Cervical Length Measurement and Funneling of Internal Cervical Os Detected by Transvaginal Ultrasonography - Bayramoglu, Özlem; Arslan, Murat; Yazici, F Gurkan; Erdem, Ahmet; Erdem, Mehmet; Bayramoglu, Koray; Camdeviren, Handan (American Journal of Perinatology, 2005)