The Restrictively Preconditioned Conjugate Gradient Methods on Normal Residual for Block Two-by-Two Linear Systems. Journal of Computational Mathematics, [S. l.], v. 26, n. 2, p. 240–249, 2018. Disponível em: https://global-sci.com/index.php/JCM/article/view/11877. Acesso em: 6 dec. 2025.