Vinca, Arta. “Assessing Instrument Reliability and Validity in Exploring Teacher’s Roles and Attitude in ESP”. International Journal of Sciences: Basic and Applied Research (IJSBAR) 36, no. 2 (September 27, 2017): 71–80. Accessed May 3, 2024. https://www.gssrr.org/index.php/JournalOfBasicAndApplied/article/view/8170.