Bondarenko, L. N., and P. F. Zhuk. “Exact Estima Tes for the Rate of Convergence of the <em class="a-Plus-plus">s</Em&gt;-Step Method of Steepest Descent in Eigenvalue Problems”. Ukrains’kyi Matematychnyi Zhurnal 49, no. 12 (December 25, 1997): 1694–1699. Accessed May 18, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/5175.