ELSAYED, E. M.; ALZAHRANI, F.; ABBAS, I.; ALOTAIBI, N. H. Solutions of Some Difference Equations Systems and Periodicity. JOURNAL OF ADVANCES IN MATHEMATICS, [S. l.], v. 16, p. 8247–8261, 2019. DOI: 10.24297/jam.v16i0.8057. Disponível em: https://rajpub.com/index.php/jam/article/view/8057. Acesso em: 28 mar. 2024.