ArsaM. F., Sugand D., and Somantri L. “The Influence of GIS Learning Material on Spatial Thinking of Students in SMA/MAN Banda Aceh ”. International Conference on Elementary Education, Vol. 2, no. 1, Mar. 2020, pp. 480-5, http://proceedings.upi.edu/index.php/icee/article/view/653.