Saiffullah, M. F. ., GERIJIH, D. D., Yunus, F. A. N. ., Rahim, M. B. ., & Ali, K. F. . (2022). Commercial HVAC Maintenance Instructional Video. Research and Innovation in Technical and Vocational Education and Training, 2(2), 061-068. https://penerbit.uthm.edu.my/periodicals/index.php/ritvet/article/view/5155