ZHANG, G. The spectrum theory of the discrete Schrödinger operator and its application. Malaya Journal of Matematik, India, v. 11, n. S, p. 125–148, 2023. DOI: 10.26637/mjm11S/009. Disponível em: https://www.malayajournal.org/index.php/mjm/article/view/654. Acesso em: 20 may. 2024.