Funa, A. A., and F. T. Talaue. “Constructivist Learning Amid the COVID-19 Pandemic: Investigating Students’ Perceptions of Biology Self-Learning Modules”. International Journal of Learning, Teaching and Educational Research, vol. 20, no. 3, Mar. 2021, pp. 250-64, http://ijlter.myres.net/index.php/ijlter/article/view/144.