Pereverzev, S. V., and S. G. Solodkii. “On the Optimization of Projection-Iterative Methods for the Approximate Solution of Ill-Posed Problems”. Ukrains’kyi Matematychnyi Zhurnal, vol. 48, no. 11, Nov. 1996, pp. 1530-7, https://umj.imath.kiev.ua/index.php/umj/article/view/5207.