Omar, Mohd Zaharuddin. “Items’ Difficulty in the Lower Secondary Bahasa Melayu System Diagnostic Test (LSBMSD) Instruments”. International Journal of Psychosocial Rehabilitation 24, no. 6 (June 30, 2020): 2345–2352. Accessed July 7, 2025. https://psychosocial.com/index.php/ijpr/article/view/6703.