Chatzarakis, G. E., H. Khatibzadeh, G. N. Miliaras, and I. P. Stavroulakis. 2013. “Asymptotic Behavior of Higher-Order Neutral Difference Equations With General Arguments”. Ukrains’kyi Matematychnyi Zhurnal 65 (3): 430-50. https://umj.imath.kiev.ua/index.php/umj/article/view/2429.