Chaikovs'kyi, A.V. (2010) “Functions of shift operator and their applications to difference equations”, Ukrains’kyi Matematychnyi Zhurnal, 62(10), pp. 1408–1419. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/2965 (Accessed: 10 April 2025).