S.B. KIWNE. Periodic solutions of nonlinear finite difference systems with time delays. Malaya Journal of Matematik, India, v. 1, n. 04, p. 81–88, 2013. DOI: 10.26637/mjm104/009. Disponível em: https://www.malayajournal.org/index.php/mjm/article/view/373. Acesso em: 16 jul. 2024.