Anane, Nassima, and Mohamed Achache. “Preconditioned Conjugate Gradient Methods for Absolute Value Equations”. J. Numer. Anal. Approx. Theory 49, no. 1 (September 8, 2020): 3–14. Accessed April 25, 2024. https://ictp.acad.ro/jnaat/journal/article/view/1197.