H. E. Putri, I. Muqodas, A. S. Sasqia, A. Abdulloh, and A. Yuliyanto, “Increasing self-regulated learning of elementary school students through the concrete-pictorial-abstract approach during the COVID-19 pandemic”, Prem. Educ. J. Pendidik. Dasar dan Pembelajaran, vol. 10, no. 2, pp. 187 – 202, Dec. 2020.