ZHANG, B. G.; YAN, P. OSCILLATION AND COMPARISON THEOREMS FOR NEUTRAL DIFFERENCE EQUATIONS. Tamkang Journal of Mathematics, [S. l.], v. 25, n. 4, p. 343–352, 1994. DOI: 10.5556/j.tkjm.25.1994.4463. Disponível em: https://journals.math.tku.edu.tw/index.php/TKJM/article/view/4463. Acesso em: 22 jul. 2024.