D. . Delawanti Chrisyarani and P. Sulistyowati, “Design and validation of thematic e-modules: optimization of problem solving-based learning ”, J. Pendidik. Dasar Nusant, vol. 7, no. 2, pp. 344–353, Jan. 2022, doi: 10.29407/jpdn.v7i2.16811.