1. Ectopic pregnancy—United States, 1990-1992;Centers for Disease Control and Prevention;MMWR Morb Mortal Wkly Rep,1995
2. Trends in ectopic pregnancy in Canada;Hockin;Can Med Assoc J,1984
3. Increase of ectopic pregnancy in Finland—combination of time and cohort effects;Makinen;Obstet Gynecol,1989
4. Changing incidences of ectopic pregnancy in Norway—a population-based study, 1970-1993;Skjeldestad;Acta Obstet Gynecol Scand,1997
5. Epidemiology of ectopic pregnancy;Chow;Epidemiol Rev,1987