参考
1. Kadar N, Caldwell B, Romero R. A Method of Screening for Ectopic Pregnancy and Its Indications. Obstet Gynecol. 1981;58(2):162-6. - Pubmed
2. Kadar N, Bohrer M, Kemmann E, Shelden R. The Discriminatory Human Chorionic Gonadotropin Zone for Endovaginal Sonography: A Prospective, Randomized Study. Fertil Steril. 1994;61(6):1016-20. doi:10.1016/s0015-0282(16)56749-1 - Pubmed