Ong, Tze Ching, et al. “Faktor-Faktor Yang Mempengaruhi Keterlibatan Pelajar Bidang Teknologi Kimpalan Dalam Ko-Kurikulum Di Kolej Vokasional: Factors That Influence Welding Technology Students’ Involvement in Co-Curriculum at Vocational College”. Online Journal for TVET Practitioners, vol. 6, no. 2, Sept. 2021, pp. 80-90, https://penerbit.uthm.edu.my/ojs/index.php/oj-tp/article/view/9530.