1Naoki.Tsukamoto,and Tsuyoshi Iwasaka ect.Gestational trophoblastic disease in women aged 50 or more[J].Gynecologic oncology,1985,20:53-61.
2Zoltan L.Band,Irwin Schoen,and Marilyn Waters.An algorithm for testing and reporting serum choriogonadotropin at clinically significant decision levels with use of "pregnancy test"reagents[J].Clinical Chemistry,1989,(35-4):545-551.
3Khanlian SA,Smith HO,Cole LA.Persistent low levels of human chorionic gonadotropin:A premalignant gestational trophoblastic disease[J].Am J Obstet Gynecol,2003,188(5):1254-1259.
4Okamoto T,Niu R,Mizutami S,et al.Levels of placenta growth in gestational tropholblastic disease[J].Am J obstet Gynecol,2003,188(1):135-140.