Lakaev Sh., Ismoilov G., Esonov E. “ Threshold Analysis for Schrödinger Operator on the One-and-Two Dimensional Lattices”. International Journal of Advanced Science and Technology 29, no. 11s (June 5, 2020): 1470 - 1479. Accessed September 16, 2021. https://sersc.org/journals/index.php/IJAST/article/view/21104.