Munjin, R. Akhmad, et al. “E-Learning System Transformation Policy through Universal Service Obligation Optimization to Interest in Student Learning in Bogor District”. International Journal of Sciences: Basic and Applied Research (IJSBAR), vol. 36, no. 2, Sept. 2017, pp. 27-47, https://gssrr.org/JournalOfBasicAndApplied/article/view/8061.