1. Universidade da Beira Interior, Centro de Matemática e Aplicações (CMA-UBI), Avenida Marquês d’Avila e Bolama, Covilhã, Portugal;
2. Center of Mathematics, University of Minho, Braga, Portugal;
3. Portugal Center for Computational and Stochastic Mathematics, University of Lisbon, Lisbon, Portugal;
4. Portugal Center of Statistics and Applications, University of Lisbon, Lisbon, Portugal