1. « Mario Negri » Institute for Pharmacological Research, Milan
2. Institute of Social and Preventive Medicine, University of Lausanne, Lausanne, Switzerland
3. International Agency for Research on Cancer, 69372, Lyon, France
4. Institute of Medical Statistics, University of Milan, Milan
5. Institute of Statistics, University of Trento, Trento, Italy
6. National Cancer Institute, Milan
7. Inter-University Consortium of Lombardy for Automatic Data Processing, Segrate - Milan