1. Exodus. Brenton L. Septuagint LXX in English. London: Bagster and sons; 1851.
2. Data 2010: National Center for Health Statistics; 2009.
3. Antenatal testing: a reevaluation. Executive summary of a Eunice Kennedy Shriver National Institute of Child Health and Human Development workshop;Signore;Obstet Gynecol,2009
4. The amplification and recording of faetal heart sounds;Gunn;Proc R Soc Med,1953
5. On the direct measurement of the electrical activity of the human heart from the esophagus and the ECG of the fetus;Cremen;Med Wschr,1906