Peen, T. Y., and M. Y. Arshad. “COLLABORATIVE AND SELF-DIRECTED LEARNING PROCESSES: A CASE STUDY IN MALAYSIAN CHEMISTRY PBL LESSON”. IJER - INDONESIAN JOURNAL OF EDUCATIONAL REVIEW, Vol. 4, no. 1, July 2017, pp. 1 - 13, doi:10.21009/IJER.04.01.01.