“Combinative Preconditioners of Modified Incomplete Cholesky Factorization and Sherman-Morrison-Woodbury Update for Self-Adjoint Elliptic Dirichlet-Periodic Boundary Value Problems”. Journal of Computational Mathematics, vol. 22, no. 6, July 2021, pp. 833-56, https://www.global-sci.com/index.php/JCM/article/view/11677.