1. Routine or selective ultrasound examinations in early pregnancy;Beifrage;Obstet Gynecol,1987
2. Multiple pregnancy;Benirschke;N Engl J Med,1973
3. Characterization of the growth discordant twin;Blickstein;Obstet Gynecol,1987
4. Mort d'un jumeau in utero et complications cerebrales chez le survivant;ChoulotJJ;Presse Med,1985
5. Effect of antenatal dexameth asone administration on the prevention of respiratory distress syndrome;Collaborative;Am J Obstet Gynecol,1981