2 citations to https://www.mathnet.ru/rus/symm3

1. Osama Moaaz, Hamida Mahjoub, Ali Muhib, “On the Periodicity of General Class of Difference Equations”, Axioms, 9:3 (2020), 75  
2. George E. Chatzarakis, Elmetwally M. Elabbasy, Osama Moaaz, Hamida Mahjoub, “Global Analysis and the Periodic Character of a Class of Difference Equations”, Axioms, 8:4 (2019), 131