1. Ectopic pregnancy;Carson;N Engl J Med.,1993
2. Emergency department diagnosis of ectopic pregnancy;Stovall;Ann Emerg Med.,1990
3. Ectopic pregnancy:ten common pitfalls in diagnosis;Abbott;Am J Emerg Med.,1990
4. hCG, progesterone, alpha-fetoprotein, and estradiol in the identification of ectopic pregnancy;Grosskinsky;Obstet Gynecol.,1993
5. β-hCG as a diagnostic aid for suspected ectopic pregnancy;Schwartz;Obstet Gynecol.,1980