Saeed, Abdulkafi. “An Adaptive Preconditioner Matrix on N-P Group AOR Iterative Poisson Solver”. Journal of Progressive Research in Mathematics 10, no. 1 (December 1, 2016): 1448-1453. Accessed April 25, 2024. http://scitecresearch.com/journals/index.php/jprm/article/view/952.