Angelova, Ivanka. “Error Estimates of High-Order Difference Schemes for Elliptic Equations With Intersecting Interfaces”. Ann. Sofia Univ. Fac. Math. and Inf. 99 (December 12, 2009): 85–109. Accessed December 4, 2024. https://ftl5.uni-sofia.bg/index.php/fmi/article/view/114.