Do Serum Beta-Human Chorionic Gonadotropin Levels on Day 4 Following Methotrexate Treatment of Patients with Ectopic Pregnancy Predict Successful Single-Dose Therapy? - Gabbur, Nagaraj; Sherer, David M; Hellmann, Mira; Abdelmalek, Ehab; Phillip, Patrina; Abulafia, Ovadia (American Journal of Perinatology, 2006)