C. Jampas, Lucell, et al. “Perceptions and Preferred Teaching Methods in Physics of At-Risk Senior Students in Biliran, Philippines”. International Journal of Sciences: Basic and Applied Research (IJSBAR), vol. 25, no. 2, Feb. 2016, pp. 268-84, https://www.gssrr.org/JournalOfBasicAndApplied/article/view/5176.