1. Institute of Applied Mathematics, Longyan University , Longyan Fujian 364012 , P.R. China
2. Department of Mathematics, University of Peshawar , Peshawar 25000 , Pakistan
3. Financial Mathematics and Actuarial Science (FMAS)-Research Group, Department of Mathematics, Faculty of Science, King Abdulaziz University , P.O. Box 80203 , Jeddah 21589 , Saudi Arabia
4. Department of Mathematics and Computer Science, Alabama State University , Montgomery , AL 36101 , United States of America