OKTAVIANDA, M.; RISTIONO, R.; FITRI, R.; SYAMSURIZAL, S. Correlation Between Learning Difficulties and Learning Motivation with Students Learning Outcomes on Online Learning in Class VIII at SMP Negeri 13 Padang. Ruang-ruang Kelas : Jurnal Pendidikan Biologi, v. 1, n. 1, p. 40-44, 4 dez. 2021.