8ReneC, Carlo C,Lucia P, et al. Umbilical amino acid concemtrations in nomal and growth-retarded fetusts sampled in utero by cordocentesis[J].Am J Obstet Gy- necol,2009; 12(162): 254.
9Cetin I, Corbetta C, Sereni LP, et al. Umbilical amino acid concemtra- tions in nomal and growth-retarded fetusts sampled in utem by cordo- centesis. Am J Obstet Gynecol,1990,162( 1 ) : 253-261.