1. Université de Pau et des Pays de l’Adour, LMAP (UMR E2S-UPPA CNRS 5142), Bat. IPRA, Avenue de l’Université F-64013 Pau, France
2. Institute of Mathematics of UFRC RAS, 112, Chernyshevsky str., 450008, Ufa, Russia
3. Instituto de Matemática e Estatística, Universidade Federal de Goiás, 74001-970, Goiania, Brazil
4. Research Institute of Mathematics, Seoul National University, Seoul 08826, South Korea