KHALID; RAHMAN, Ghani; HAMID, Abdul. Effect of English Non-Modal Operators on Proficiency and Performance of Undergraduate Students in Hazara University, Pakistan. Liberal Arts and Social Sciences International Journal (LASSIJ), Peshawar, Pakistan, v. 4, n. 1, p. 271–281, 2020. DOI: 10.47264/idea.lassij/4.1.23. Disponível em: https://ideapublishers.org/index.php/lassij/article/view/215. Acesso em: 4 nov. 2025.