HuangTing-Zhu, and WuChi-Yе. 2016. “Perturbation and Error Analyses of Partitioned LU factorization for Block Tridiagonal Linear Systems”. Ukrains’kyi Matematychnyi Zhurnal 68 (12), 1683-95. https://umj.imath.kiev.ua/index.php/umj/article/view/1953.