7Klock S C, Greenfeld D A. Psychological status of in vitro fertilization patients during pregnancy : A longitudinal study [ J]. Fertil Steril, 2009,73(6) :1159-1164.
8Bohn H. Detection and characterization of pregnancy proteins in the human plaeenta and their quantitative immunochemical determination in sera from pregaaant women[ J ]. Arch Gynakol, 1971,210 (4) :440 - 457.
