UCL - SC/PHYS - Département de physique, Concordia University, Montréal - Department of Mathematics and Statistics, Bialystok University - Dept. Mathematics, Bulgarian Academy of Sciences, Sofia - Dept. Mathematics, Antoine, Jean-Pierre, Ali, Syed Twareque, Lisiecki, W., Mladenov, Ivailo M., Odzijewicz, Anatol, UCL - SC/PHYS - Département de physique, Concordia University, Montréal - Department of Mathematics and Statistics, Bialystok University - Dept. Mathematics, Bulgarian Academy of Sciences, Sofia - Dept. Mathematics, Antoine, Jean-Pierre, Ali, Syed Twareque, Lisiecki, W., Mladenov, Ivailo M., and Odzijewicz, Anatol