TY - JOUR AN - 14 AU - Sherer ,D.M. AU - Liberto ,L. AU - Woods ,J.R. TI - Preoperative sonographic diagnosis of a unilateral tubal twin gestation with documented fetal heart activity. JO - Ultrasound Med PY - 1990 VL - 9 SP - 729 M2 - 729 ER -