Paukštaitė, Gailė, and Artūras Štikonas. “Classification of the Nullity for the Second Order Discrete Nonlocal Problems”. Lietuvos matematikos rinkinys 55, no. A (December 22, 2014): 40–45. Accessed November 21, 2024. https://journals.vu.lt./LMR/article/view/14909.