1. Department of Automatic Control, Computers and Electronics, University Petroleum-Gas of Ploiesti, Ploiești, Romania
2. Department of Mathematics, University Jaume I of Castellón, Spain
3. Department of Statistics, National Autonomous University of Mexico, Mexico City, Mexico
4. Research Group on Statistics, Econometrics and Health (GRECS), University of Girona, Spain
5. CIBER of Epidemiology and Public Health, University of Girona, Spain