Institution: | a Department of Statistics and Operations Research, University of Vigo, Faculty of Business Sciences, Campus South, Ourense, 32004, Spain b Department of Mathematics, University of A Coruña, Faculty of Computer Sciences, Campus de Elviña, A Coruña, Spain c Department of Statistics and Operations Research, University of Santiago de Compostela, Faculty of Mathematics, Campus South, Santiago de Compostela, Spain |