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3. ACOG (American College of Obstetricians and Gynecologists) (2003) Dystocia and augmentation of labor. ACOG Practice Bull 49
4. ACOG (American College of Obstetricians and Gynecologists) (2004) Inappropriate use of the terms fetal distress and birth asphyxia. Com Opinion 303
5. Albers LL (1999) The duration of labor in healthy women. J Perinatol 19: 114