Bakar, Ramli. “The Effect of Learning Motivation on Student?S Productive Competencies in Vocational High School, West Sumatra”. International Journal of Asian Social Science 4, no. 6 (June 2, 2014): 722–732. Accessed May 15, 2025. https://www.archive.aessweb.com/index.php/5007/article/view/2672.