SCIENTIFIC RESEARCH ACTIVITIES AT HANOI UNIVERSITY. Journal of Foreign Language Studies, [S. l.], n. 10, p. 91–92, 2007. DOI: 10.56844/tckhnn.10.385. Disponível em: http://journals.hanu.edu.vn/index.php/tckhnn/article/view/385. Acesso em: 15 jan. 2026.