THI, H. D. . Factors Influence Learners’ English Speaking Skill at a Vietnamese University and Suggestions for Improvement. Social Science Learning Education Journal, [S. l.], v. 6, n. 06, p. 455–465, 2021. Disponível em: https://www.sslej.in/index.php/sslej/article/view/3476. Acesso em: 27 sep. 2026.