1. The ultrasonic changes in the maturing placenta and their relation to fetal pulmonic maturity;Grannum;Am J Obstet Gynecol,1979
2. Amniocentesis;Schwatz;Clin Obstet Gynecol,1975
3. Kirshen ET, Bernirschke K. Fetal examination after amniocentesis. Obstet Gynecol 1973;42:615.
4. Report on third trimester amniocentesis at Prentice Women’s Hospital of Northwestern University Medical School, Chicago, Illinois;Sabbagha,1979
5. Young BK. Report on third trimester amniocentesis at Bellevue Hospital of New York University Medical Center, New York, New York. In: Antenatal Diagnosis: Report of a Consensus Development Conference, Bethesda, Maryland: National Institutes of Health, 1979: pp. 11–65.