Affiliation: | 1 Division of Biostatistics, Department of Public Health & Preventive Medicine, Oregon Health & Sciences University, Mail Code CR145, Oregon 97239-3098, U.S.A. pierced{at}ohsu.edu, 2 Department of Statistics, University of Udine, via Treppo 18, I-33100 Udine, Italy. bellio{at}dss.uniud.it |