Mehiddin Al-Baali, Sultan Qaboos University, Department of Mathematics and Statistics, Muscat, Oman.
Lucio Grandinetti, Dipartimento di Ingegneria Informatica, Modellistica, Elettronica e Sistemistica, Calabria University, Arcavacata di Rende, Italy.
Anton Purnama, Sultan Qaboos University, Department of Mathematics and Statistics, Muscat, Oman.