1. Radiation Epidemiology Branch and Environmental Epidemiology Branch, Epidemiology and Biostatistics Program, National Cancer Institute, National Institutes of Health, Public Health Service, U. S. Department of Health and Human Services, Bethesda, Maryland
2. International Agency for Research on Cancer, Lyon, France
3. Cancer Registry of Norway, Norwegian Radium Hospital, Oslo, Norway
4. Birmingham Cancer Registry, Queen Elizabeth Medical Centre, Birmingham, United Kingdom
5. Manitoba Cancer Registry, University of Manitoba Faculty of Medicine, Winnipeg, Manitoba, Canada