8Titnor-Tristsch IF,Monteagudo A,Preis ner DB,High-frequency transvaginal sonographic examination for the potential malformation assessment of the 9-week to 14-week[J].Fetus J Clin Utrasoud, 2002,20(1) : 231-238.
9Tristsch IF,Monteagudo A,Preisner DB.High-frequency transvaginal sonographic examination for the potential malformation assessment of the 9-week to 14-week[J].Fetus J ClinUtrasoud,2002,20(1):231.