Bernadette Faye
Department of Mathematics, University Alioune Diop de Bambey,Bambey,Senegal
Laszlo Nemeth
Department of Mathematics, Institute of Basic Sciences, University of Sopron,Sopron,Hungary; Department of Mathematics, J. Selye University,Kom a ́rno,Slovakia
Laszlo Szalay
Department of Mathematics, Institute of Basic Sciences, University of Sopron,Sopron,Hungary; Department of Mathematics, J. Selye University,Kom a ́rno,Slovakia