1. Department of Mathematics Shaheed Benazir Bhutto University, Sheringal Dir(U) Khyber Pakhtunkhwa Pakistan
2. Department of Mathematics and General Sciences Prince Sultan University Riyadh Saudi Arabia
3. CONACyT‐Tecnológico Nacional de México/CENIDET. Interior Internado Palmira S/N, Col. Palmira, C.P. 62490 Cuernavaca Morelos México