7Richard L Sweet, Ronald S. Infectious diseases of the female genital tract 1995, 64t 355.
8Bruce J. Fundamental Elements of the Quality of care: A simple framework. Studies in Family Planning, 1990, 21 (2): 61.
9King J C. The risk of maternal nutritional depletion and poor outcomes increases in early or closely spaced pregnancies [ J ]. J Nutr, 2003,133 (SSuppl 2) : S1732-S1736.
10DaVanzo J, Hale L, Razzaque A, et al. Effects of interpregnancy interval and outcome of the preceding pregnancy on pregnancy outcomes in Matlab, Bangladesh [ J ]. BJOG, 2007, 114 ( 9 ) : 1079-1087.
