1. Imtiaz Ahmad:
Department of Mathematics, University of Malakand,Chakdara,Pakistan
2. Muhammad Iqbal:
Department of Mathematics, University of Malakand,Chakdara,Pakistan
3. Muhammad Rashad:
Department of Mathematics,
University of Malakand, Chakdara, Pakistan.
4. Amanullah:
Department of Mathematics,
University of Malakand, Chakdara, Pakistan