1. Births: Final data for 2004;Martin;Natl Vital Stat Rep,2006
2. Births: Final data for 2002;Martin;Natl Vital Stat Rep,2003
3. Explaining the 2001-02 infant mortality increase: Data from the linked birth/infant death data set;MacDorman;Natl Vital Stat Rep,2005
4. Births: Final data for 2003;Martin;Natl Vital Stat Rep,2005
5. The control of labor;Norwitz;N Engl J Med,1999