ITEIWI, A. M. On a Numerical-Analytic method for second-order difference equations. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 48, n. 7, p. 920–924, 1996. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/5264. Acesso em: 5 dec. 2025.