El-Mowafy, N.; Helal, S. M.; El-Azab, M. S. Study the Influence of Nonlocal Boundary Condition on the Difference Eigenvalue Problem for Elliptic Partial Differential Equation. Jour. Inform. Math. Sci. 2020, 12 (3), 209-222. https://doi.org/10.26713/jims.v12i3.1408.