1. Epidemiology of twins;Monteagudo,1998
2. Prenatal diagnosis of congenital anomalies;Romero,1988
3. The pathology of the human placenta;Bernirschke,1995
4. Prenatal ultrasound diagnosis of conjoined twins;Van den Brand;Obstet Gynecol Surv,1995
5. The abnormalities and genesis of cephalopagus (Janiceps) twins;Sturock;Anat Anz,1973