D. A. Septiani, A. A. A. T. Handayani, H. Hermansyah, A. Syukur, and J. Jamaluddin, “E-module innovation as a learning solution for chemistry course during the pandemic based on problem-based learning”, J. Pijar.MIPA, vol. 16, no. 4, pp. 459–465, Sep. 2021.