Effendi , R., S. Joyoatmojo, and D. Sulistyaningrum. “Analisis Kebutuhan Media E-Learning Berbasis Schoology Di SMK Negeri Kota Surakarta”. Surya Edunomics, Vol. 2, no. 1, May 2019, pp. 34-44, https://ebook.umpwr.ac.id/suryaedunomics/article/view/1056.