หาญมนตรี อ. Verb to be: The Most Powerful Auxiliary Verb in English. Liberal Arts Review, [S. l.], v. 13, n. 26, p. 1–17, 2018. Disponível em: https://so04.tci-thaijo.org/index.php/larhcu/article/view/156467. Acesso em: 29 mar. 2024.