BoichukО. A., and S. M. Chuiko. 2008. “Method of Accelerated Convergence for the Construction of Solutions of a Noetherian Boundary-Value Problem”. Ukrains’kyi Matematychnyi Zhurnal 60 (12), 1587–1601. https://umj.imath.kiev.ua/index.php/umj/article/view/3273.