Viet Hung N. STUDY OF THE EXISTENCE AND STABILITY OF SPATIAL SOLITON BEAMS IN HIGHER-ORDER NONLINEAR OPTICAL FIBERS WITH GAIN AND LOSS. HNUE JoNS [Internet]. 2026 Sep. 30 [cited 2026 Oct. 17];71(3):53-65. Available from: https://hnuejs.edu.vn/ns/article/view/1601