Panrat, Thanut, and Vimolchaya Yanasugondha. 2024. “A Corpus-Based Study of English Synonyms Clear, Obvious, Apparent, and Evident: Implications for ELT”. LEARN Journal: Language Education and Acquisition Research Network 17 (1):162-87. https://so04.tci-thaijo.org/index.php/LEARN/article/view/270381.