1. Who has gallstones? Recent epidemiological investigations (in Danish);Jørgensen;Nord Med,1992
2. Has laparoscopic cholecystectomy changed patterns of practice and patient outcome in Ontario?;Cohen;Can Med Assoc J,1996
3. Trends in incidence, clinical findings and outcome of acute and elective cholecystectomy. 1970–1986;Kullman;Eur J Surg,1994
4. Rise and fall in the number of cholecystectomies;Muhrbeck;Eur J Surg,1996
5. Maximum Waiting Time Guarantee. Monitoring and Evaluation (in Swedish). National Board of Heath and Welfare 1994, Stockholm.