CAO, T. B.; LIU, K.; LIU, X. L. The properties on differential-difference polynomials. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 69, n. 1, p. 71–82, 2017. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/1676. Acesso em: 5 dec. 2025.