1. Fetal and umbilical Doppler ultrasound in high-risk pregnancies;Alfirevic;Cochrane Database Syst Rev,2010
2. Fetal and umbilical Doppler ultrasound in normal pregnancy;Alfirevic;Cochrane Database Syst Rev,2010
3. Utero-placental Doppler ultrasound for improving pregnancy outcome;Stampalija;Cochrane Database Syst Rev,2010
4. Doppler ultrasound for fetal assessment in high risk pregnancies;Neilson;Cochrane Database Syst Rev,1996
5. Doppler ultrasound for fetal assessment in high risk pregnancies;Alfirevic;Cochrane Database Syst Rev,2000