Putra, Z. H., Y. M. Afrillia, Dahnilsyah, and H. Tjoe. “Prospective Elementary teachers’ Informal Mathematical Proof Using GeoGebra: The Case of 3D Shapes”. Journal on Mathematics Education, vol. 14, no. 3, June 2023, pp. 449-68, doi:10.22342/jme.v14i3.pp449-468.